Initial Flutter booru app

.gitignore

@@ -0,0 +1,10 @@
+.dart_tool/
+.packages
+build/
+/isar.dll
+.idea/
+*.iml
+.flutter-plugins
+.flutter-plugins-dependencies
+android/local.properties
+*.log

.metadata

@@ -0,0 +1,36 @@
+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: "ff37bef603469fb030f2b72995ab929ccfc227f0"
+  channel: "stable"
+
+project_type: app
+
+# Tracks metadata for the flutter migrate command
+migration:
+  platforms:
+    - platform: root
+      create_revision: ff37bef603469fb030f2b72995ab929ccfc227f0
+      base_revision: ff37bef603469fb030f2b72995ab929ccfc227f0
+    - platform: android
+      create_revision: ff37bef603469fb030f2b72995ab929ccfc227f0
+      base_revision: ff37bef603469fb030f2b72995ab929ccfc227f0
+    - platform: linux
+      create_revision: ff37bef603469fb030f2b72995ab929ccfc227f0
+      base_revision: ff37bef603469fb030f2b72995ab929ccfc227f0
+    - platform: windows
+      create_revision: ff37bef603469fb030f2b72995ab929ccfc227f0
+      base_revision: ff37bef603469fb030f2b72995ab929ccfc227f0
+
+  # User provided section
+
+  # List of Local paths (relative to this file) that should be
+  # ignored by the migrate tool.
+  #
+  # Files that are not part of the templates will be ignored by default.
+  unmanaged_files:
+    - 'lib/main.dart'
+    - 'ios/Runner.xcodeproj/project.pbxproj'

README.md

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+# GelRuleApp
+
+GelRuleApp is a single Flutter monolith for browsing booru/gelbooru/rule34-like providers with a Pinterest-style feed. It does not start or require a separate backend server. Provider access, caching, favorites, collections, search history, settings, and health checks all run locally inside the Flutter app.
+
+## Stack
+
+- Dart and Flutter
+- Riverpod for dependency injection
+- Dio for provider HTTP APIs
+- Isar for local storage
+- connectivity_plus for network state
+- build_runner with Isar/freezed/json_serializable dependencies available for generated code workflows
+- go_router for navigation
+- cached_network_image and flutter_staggered_grid_view for the Pinterest-style feed
+- media_kit for video posts
+
+## Structure
+
+- `lib/core/http`: Dio setup, retry/backoff, network info
+- `lib/core/database`: Isar database and entity mappings
+- `lib/core/cache`: metadata cache helpers
+- `lib/core/errors`: app exceptions and failures
+- `lib/core/utils`: `Result<T>` and logging
+- `lib/backend/models`: domain models
+- `lib/backend/providers`: provider interface, concrete providers, factory, manager
+- `lib/backend/repositories`: local persistence access
+- `lib/backend/services`: app-facing service layer
+- `lib/backend/di`: Riverpod providers
+- `lib/app`: app shell, router, theme, responsive helpers
+- `lib/shared/widgets`: reusable UI pieces
+- `lib/features`: feed, post details, search, favorites, collections, providers, settings
+
+## Frontend Routes
+
+- `/`: masonry feed
+- `/search`: recent searches and autocomplete
+- `/post/:providerId/:postId`: post details
+- `/favorites`: favorite posts
+- `/collections`: boards
+- `/collections/:collectionId`: posts inside a collection
+- `/providers`: provider management
+- `/providers/new`: provider form for create/edit
+- `/providers/check`: provider health checks
+- `/settings`: app settings
+
+## Frontend And Backend Integration
+
+The UI calls backend services through Riverpod providers from `lib/backend/di/backend_providers.dart`.
+
+- `FeedController` calls `FeedService`, `SearchService`, and `ProviderManager`.
+- `PostDetailsScreen` uses cached post metadata first, then `ProviderManager.getPost`.
+- `PostCard` and details actions call `FavoriteService` and `CollectionService`.
+- Provider screens call `ProviderManager` and `ProviderCheckService`.
+- Settings call `SettingsService` and `CacheService`.
+
+Business logic stays in backend/core services. UI controllers only coordinate state and user actions.
+
+## Providers
+
+The MVP ships with seed configs for:
+
+- Gelbooru: `https://gelbooru.com`
+- Rule34: `https://api.rule34.xxx`
+- Safebooru: `https://safebooru.org`
+
+Providers implement:
+
+```dart
+abstract class ContentProvider {
+  String get id;
+  String get name;
+  String get baseUrl;
+
+  Future<List<Post>> searchPosts({
+    required List<String> tags,
+    required int page,
+    int limit = 50,
+    String? rating,
+  });
+
+  Future<Post?> getPost(String id);
+  Future<ProviderHealth> checkHealth();
+}
+```
+
+Gelbooru and Rule34 use the Gelbooru-compatible dapi endpoint:
+
+```text
+/index.php?page=dapi&s=post&q=index&json=1
+```
+
+Danbooru uses:
+
+```text
+/posts.json
+```
+
+All provider responses are normalized to `Post`.
+
+## Adding A Provider
+
+1. Add a mapper in `lib/backend/mappers`.
+2. Implement `ContentProvider` in `lib/backend/providers`.
+3. Register the `apiType` in `ProviderFactory`.
+4. Save a `ContentProviderConfig` with `ProviderManager.addCustomProvider`.
+
+For custom providers, MVP supports these `apiType` values:
+
+- `gelbooru`
+- `rule34`
+- `danbooru`
+
+Unsupported types return `ProviderUnavailableException` instead of crashing the app.
+
+## ProviderManager
+
+`ProviderManager` loads enabled provider configs from Isar, sorts them by `priority`, creates provider instances through `ProviderFactory`, checks health, and performs multi-provider search.
+
+Search behavior:
+
+- Offline providers are skipped based on saved health.
+- A failed provider marks itself offline.
+- Other providers continue returning posts.
+- Results are combined into a single list.
+
+## Health Checks
+
+Use `ProviderCheckService`:
+
+```dart
+final health = await ref
+    .read(providerCheckServiceProvider)
+    .checkOne('gelbooru');
+
+final all = await ref
+    .read(providerCheckServiceProvider)
+    .checkAll();
+```
+
+`checkAll()` runs in parallel with a concurrency limit of 3 and saves `ProviderHealth` in Isar.
+
+## Using Services From Flutter UI
+
+Initialize your app with Riverpod:
+
+```dart
+ProviderScope(
+  child: MyApp(),
+);
+```
+
+Load a feed:
+
+```dart
+final feed = ref.read(feedServiceProvider);
+final result = await feed.refresh(
+  tags: ['landscape'],
+  rating: 'safe',
+);
+```
+
+Infinite scroll:
+
+```dart
+final next = await ref.read(feedServiceProvider).loadNextPage(
+  tags: ['landscape'],
+);
+```
+
+Search history:
+
+```dart
+final search = ref.read(searchServiceProvider);
+final tags = search.parseTags('cat cute');
+await search.saveSearch('cat cute', 120);
+final recent = await search.recentSearches();
+```
+
+Favorites:
+
+```dart
+await ref.read(favoriteServiceProvider).addFavorite(post);
+final saved = await ref
+    .read(favoriteServiceProvider)
+    .isFavorite(post.id, post.providerId);
+```
+
+Collections:
+
+```dart
+final collection = await ref
+    .read(collectionServiceProvider)
+    .createCollection('Inspiration', 'Reference posts');
+
+await ref
+    .read(collectionServiceProvider)
+    .addPostToCollection(collection.data.id, post);
+```
+
+Settings export/import:
+
+```dart
+final settings = ref.read(settingsServiceProvider);
+final json = await settings.exportSettingsToJson();
+await settings.importSettingsFromJson(json.data);
+```
+
+## Local Storage
+
+Isar stores:
+
+- provider configs
+- provider health
+- cached post metadata
+- favorites
+- collections
+- collection-post links
+- search history
+- app settings
+
+Post cache stores metadata only. It does not download or persist original media files.
+
+## Safety Notes
+
+- The app requests API metadata only.
+- It does not bypass site limits or authentication.
+- Dio uses a clear User-Agent.
+- Retry is limited and uses exponential backoff.
+- Provider failures are isolated so one offline provider does not break the feed.
+
+## Development
+
+Fetch dependencies:
+
+```bash
+flutter pub get
+```
+
+On Windows, Flutter plugins require Developer Mode for symlink support. If `flutter pub get` or desktop builds show a symlink warning, enable Developer Mode in Windows settings.
+
+Generate Isar code:
+
+```bash
+dart run build_runner build --delete-conflicting-outputs
+```
+
+Run tests:
+
+```bash
+flutter test
+```
+
+Run the app:
+
+```bash
+flutter run -d windows
+flutter run -d linux
+flutter run -d android
+```
+
+Build release artifacts:
+
+```bash
+flutter build windows
+flutter build linux
+flutter build apk
+```
+
+Notes:
+
+- Windows builds require Windows Developer Mode when plugins are used.
+- Linux builds must be run on a Linux host.
+- Android builds require Android SDK and `ANDROID_HOME`.
+
+## Adding A Screen
+
+1. Add a route in `lib/app/router.dart`.
+2. Add feature state/controller/screen under `lib/features/<name>/presentation`.
+3. Use backend providers from `backend_providers.dart`; do not recreate Dio, Isar, or provider logic in UI code.
+4. Add loading, error, empty, and success states.

analysis_options.yaml

@@ -0,0 +1,9 @@
+include: package:flutter_lints/flutter.yaml
+
+analyzer:
+  exclude:
+    - "**/*.g.dart"
+
+linter:
+  rules:
+    avoid_print: true

android/.gitignore

@@ -0,0 +1,11 @@
+/.gradle
+/captures/
+/local.properties
+GeneratedPluginRegistrant.java
+.cxx/
+
+# Remember to never publicly share your keystore.
+# See https://flutter.dev/to/reference-keystore
+key.properties
+**/*.keystore
+**/*.jks

android/app/build.gradle.kts

@@ -0,0 +1,44 @@
+plugins {
+    id("com.android.application")
+    id("kotlin-android")
+    // The Flutter Gradle Plugin must be applied after the Android and Kotlin Gradle plugins.
+    id("dev.flutter.flutter-gradle-plugin")
+}
+
+android {
+    namespace = "com.example.gel_rule_app"
+    compileSdk = flutter.compileSdkVersion
+    ndkVersion = flutter.ndkVersion
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+
+    kotlinOptions {
+        jvmTarget = JavaVersion.VERSION_17.toString()
+    }
+
+    defaultConfig {
+        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
+        applicationId = "com.example.gel_rule_app"
+        // You can update the following values to match your application needs.
+        // For more information, see: https://flutter.dev/to/review-gradle-config.
+        minSdk = flutter.minSdkVersion
+        targetSdk = flutter.targetSdkVersion
+        versionCode = flutter.versionCode
+        versionName = flutter.versionName
+    }
+
+    buildTypes {
+        release {
+            // TODO: Add your own signing config for the release build.
+            // Signing with the debug keys for now, so `flutter run --release` works.
+            signingConfig = signingConfigs.getByName("debug")
+        }
+    }
+}
+
+flutter {
+    source = "../.."
+}

android/app/src/debug/AndroidManifest.xml

@@ -0,0 +1,7 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <!-- The INTERNET permission is required for development. Specifically,
+         the Flutter tool needs it to communicate with the running application
+         to allow setting breakpoints, to provide hot reload, etc.
+    -->
+    <uses-permission android:name="android.permission.INTERNET"/>
+</manifest>

android/app/src/main/AndroidManifest.xml

@@ -0,0 +1,47 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <uses-permission android:name="android.permission.INTERNET"/>
+
+    <application
+        android:label="gel_rule_app"
+        android:name="${applicationName}"
+        android:icon="@mipmap/ic_launcher">
+        <activity
+            android:name=".MainActivity"
+            android:exported="true"
+            android:launchMode="singleTop"
+            android:taskAffinity=""
+            android:theme="@style/LaunchTheme"
+            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
+            android:hardwareAccelerated="true"
+            android:windowSoftInputMode="adjustResize">
+            <!-- Specifies an Android theme to apply to this Activity as soon as
+                 the Android process has started. This theme is visible to the user
+                 while the Flutter UI initializes. After that, this theme continues
+                 to determine the Window background behind the Flutter UI. -->
+            <meta-data
+              android:name="io.flutter.embedding.android.NormalTheme"
+              android:resource="@style/NormalTheme"
+              />
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN"/>
+                <category android:name="android.intent.category.LAUNCHER"/>
+            </intent-filter>
+        </activity>
+        <!-- Don't delete the meta-data below.
+             This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->
+        <meta-data
+            android:name="flutterEmbedding"
+            android:value="2" />
+    </application>
+    <!-- Required to query activities that can process text, see:
+         https://developer.android.com/training/package-visibility and
+         https://developer.android.com/reference/android/content/Intent#ACTION_PROCESS_TEXT.
+
+         In particular, this is used by the Flutter engine in io.flutter.plugin.text.ProcessTextPlugin. -->
+    <queries>
+        <intent>
+            <action android:name="android.intent.action.PROCESS_TEXT"/>
+            <data android:mimeType="text/plain"/>
+        </intent>
+    </queries>
+</manifest>

android/app/src/main/kotlin/com/example/gel_rule_app/MainActivity.kt

@@ -0,0 +1,5 @@
+package com.example.gel_rule_app
+
+import io.flutter.embedding.android.FlutterActivity
+
+class MainActivity : FlutterActivity()

android/app/src/main/res/drawable-v21/launch_background.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Modify this file to customize your launch splash screen -->
+<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:drawable="@color/launch_background" />
+
+    <!-- You can insert your own image assets here -->
+    <!-- <item>
+        <bitmap
+            android:gravity="center"
+            android:src="@mipmap/launch_image" />
+    </item> -->
+</layer-list>

android/app/src/main/res/drawable/launch_background.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Modify this file to customize your launch splash screen -->
+<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:drawable="@color/launch_background" />
+
+    <!-- You can insert your own image assets here -->
+    <!-- <item>
+        <bitmap
+            android:gravity="center"
+            android:src="@mipmap/launch_image" />
+    </item> -->
+</layer-list>

android/app/src/main/res/values-night/styles.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <!-- Theme applied to the Android Window while the process is starting when the OS's Dark Mode setting is on -->
+    <style name="LaunchTheme" parent="@android:style/Theme.Black.NoTitleBar">
+        <!-- Show a splash screen on the activity. Automatically removed when
+             the Flutter engine draws its first frame -->
+        <item name="android:windowBackground">@drawable/launch_background</item>
+    </style>
+    <!-- Theme applied to the Android Window as soon as the process has started.
+         This theme determines the color of the Android Window while your
+         Flutter UI initializes, as well as behind your Flutter UI while its
+         running.
+
+         This Theme is only used starting with V2 of Flutter's Android embedding. -->
+    <style name="NormalTheme" parent="@android:style/Theme.Black.NoTitleBar">
+        <item name="android:windowBackground">?android:colorBackground</item>
+    </style>
+</resources>

android/app/src/main/res/values/colors.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <color name="launch_background">#101114</color>
+</resources>

android/app/src/main/res/values/styles.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <!-- Theme applied to the Android Window while the process is starting when the OS's Dark Mode setting is off -->
+    <style name="LaunchTheme" parent="@android:style/Theme.NoTitleBar">
+        <!-- Show a splash screen on the activity. Automatically removed when
+             the Flutter engine draws its first frame -->
+        <item name="android:windowBackground">@drawable/launch_background</item>
+    </style>
+    <!-- Theme applied to the Android Window as soon as the process has started.
+         This theme determines the color of the Android Window while your
+         Flutter UI initializes, as well as behind your Flutter UI while its
+         running.
+
+         This Theme is only used starting with V2 of Flutter's Android embedding. -->
+    <style name="NormalTheme" parent="@android:style/Theme.NoTitleBar">
+        <item name="android:windowBackground">#101114</item>
+    </style>
+</resources>

android/app/src/profile/AndroidManifest.xml

@@ -0,0 +1,7 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <!-- The INTERNET permission is required for development. Specifically,
+         the Flutter tool needs it to communicate with the running application
+         to allow setting breakpoints, to provide hot reload, etc.
+    -->
+    <uses-permission android:name="android.permission.INTERNET"/>
+</manifest>

android/build.gradle.kts

@@ -0,0 +1,37 @@
+import com.android.build.gradle.LibraryExtension
+
+allprojects {
+    repositories {
+        google()
+        mavenCentral()
+    }
+}
+
+val newBuildDir: Directory =
+    rootProject.layout.buildDirectory
+        .dir("../../build")
+        .get()
+rootProject.layout.buildDirectory.value(newBuildDir)
+
+subprojects {
+    val newSubprojectBuildDir: Directory = newBuildDir.dir(project.name)
+    project.layout.buildDirectory.value(newSubprojectBuildDir)
+}
+subprojects {
+    project.evaluationDependsOn(":app")
+}
+
+subprojects {
+    plugins.withId("com.android.library") {
+        extensions.configure<LibraryExtension>("android") {
+            if (namespace == null) {
+                namespace = group.toString()
+            }
+            compileSdk = 36
+        }
+    }
+}
+
+tasks.register<Delete>("clean") {
+    delete(rootProject.layout.buildDirectory)
+}

android/gradle.properties

@@ -0,0 +1,2 @@
+org.gradle.jvmargs=-Xmx8G -XX:MaxMetaspaceSize=4G -XX:ReservedCodeCacheSize=512m -XX:+HeapDumpOnOutOfMemoryError
+android.useAndroidX=true

android/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.14-all.zip

android/gradlew

@@ -0,0 +1,160 @@
+#!/usr/bin/env bash
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn ( ) {
+    echo "$*"
+}
+
+die ( ) {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+esac
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Split up the JVM_OPTS And GRADLE_OPTS values into an array, following the shell quoting and substitution rules
+function splitJvmOpts() {
+    JVM_OPTS=("$@")
+}
+eval splitJvmOpts $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS
+JVM_OPTS[${#JVM_OPTS[*]}]="-Dorg.gradle.appname=$APP_BASE_NAME"
+
+exec "$JAVACMD" "${JVM_OPTS[@]}" -classpath "$CLASSPATH" org.gradle.wrapper.GradleWrapperMain "$@"

android/gradlew.bat

@@ -0,0 +1,90 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windowz variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+if "%@eval[2+2]" == "4" goto 4NT_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+goto execute
+
+:4NT_args
+@rem Get arguments from the 4NT Shell from JP Software
+set CMD_LINE_ARGS=%$
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

android/settings.gradle.kts

@@ -0,0 +1,26 @@
+pluginManagement {
+    val flutterSdkPath =
+        run {
+            val properties = java.util.Properties()
+            file("local.properties").inputStream().use { properties.load(it) }
+            val flutterSdkPath = properties.getProperty("flutter.sdk")
+            require(flutterSdkPath != null) { "flutter.sdk not set in local.properties" }
+            flutterSdkPath
+        }
+
+    includeBuild("$flutterSdkPath/packages/flutter_tools/gradle")
+
+    repositories {
+        google()
+        mavenCentral()
+        gradlePluginPortal()
+    }
+}
+
+plugins {
+    id("dev.flutter.flutter-plugin-loader") version "1.0.0"
+    id("com.android.application") version "8.11.1" apply false
+    id("org.jetbrains.kotlin.android") version "2.2.20" apply false
+}
+
+include(":app")

lib/app/app.dart

@@ -0,0 +1,114 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+import '../backend/backend.dart';
+import 'router.dart';
+import 'theme.dart';
+
+class GelRuleApp extends ConsumerWidget {
+  const GelRuleApp({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final database = ref.watch(appDatabaseProvider);
+    final settings = ref.watch(appSettingsProvider);
+    final router = ref.watch(appRouterProvider);
+
+    return database.when(
+      loading: () => const MaterialApp(
+        debugShowCheckedModeBanner: false,
+        home: _StartupLoadingScreen(),
+      ),
+      error: (error, _) => MaterialApp(
+        debugShowCheckedModeBanner: false,
+        theme: buildTheme(Brightness.light),
+        darkTheme: buildTheme(Brightness.dark),
+        themeMode: ThemeMode.dark,
+        home: _StartupErrorScreen(error: error),
+      ),
+      data: (_) => MaterialApp.router(
+        title: 'GelRule',
+        debugShowCheckedModeBanner: false,
+        theme: buildTheme(Brightness.light),
+        darkTheme: buildTheme(Brightness.dark),
+        themeMode: settings.maybeWhen(
+          data: (value) => parseThemeMode(value.themeMode),
+          orElse: () => ThemeMode.dark,
+        ),
+        routerConfig: router,
+      ),
+    );
+  }
+}
+
+final appSettingsProvider = FutureProvider<AppSettings>((ref) {
+  return ref.watch(settingsServiceProvider).getSettings().then(
+        (result) => result.fold(
+          onSuccess: (settings) => settings,
+          onError: (_) => AppSettings.defaults,
+        ),
+      );
+});
+
+class _StartupLoadingScreen extends StatelessWidget {
+  const _StartupLoadingScreen();
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      backgroundColor: const Color(0xFF101114),
+      body: Center(
+        child: CircularProgressIndicator(
+          color: ColorScheme.fromSeed(
+            seedColor: const Color(0xFFE84D8A),
+            brightness: Brightness.dark,
+          ).primary,
+        ),
+      ),
+    );
+  }
+}
+
+class _StartupErrorScreen extends ConsumerWidget {
+  const _StartupErrorScreen({required this.error});
+
+  final Object error;
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    return Scaffold(
+      body: SafeArea(
+        child: Center(
+          child: Padding(
+            padding: const EdgeInsets.all(24),
+            child: Column(
+              mainAxisSize: MainAxisSize.min,
+              children: [
+                const Icon(Icons.storage_rounded, size: 48),
+                const SizedBox(height: 16),
+                Text(
+                  'Could not start local database',
+                  style: Theme.of(context).textTheme.titleLarge,
+                  textAlign: TextAlign.center,
+                ),
+                const SizedBox(height: 8),
+                Text(
+                  '$error',
+                  textAlign: TextAlign.center,
+                  maxLines: 5,
+                  overflow: TextOverflow.ellipsis,
+                ),
+                const SizedBox(height: 18),
+                FilledButton.icon(
+                  onPressed: () => ref.invalidate(appDatabaseProvider),
+                  icon: const Icon(Icons.refresh_rounded),
+                  label: const Text('Retry'),
+                ),
+              ],
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+}

lib/app/responsive.dart

@@ -0,0 +1,26 @@
+import 'package:flutter/widgets.dart';
+
+class AppBreakpoints {
+  static const mobile = 700.0;
+  static const desktop = 1100.0;
+}
+
+class Responsive {
+  static bool isMobile(BuildContext context) =>
+      MediaQuery.sizeOf(context).width < AppBreakpoints.mobile;
+
+  static bool isDesktop(BuildContext context) =>
+      MediaQuery.sizeOf(context).width >= AppBreakpoints.desktop;
+
+  static int columnsFor(
+    BuildContext context, {
+    required int mobileColumns,
+    required int desktopColumns,
+  }) {
+    final width = MediaQuery.sizeOf(context).width;
+    if (width < 380) return 1;
+    if (width < AppBreakpoints.mobile) return mobileColumns.clamp(1, 2);
+    if (width < AppBreakpoints.desktop) return 3;
+    return desktopColumns.clamp(3, 8);
+  }
+}

lib/app/router.dart

@@ -0,0 +1,80 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:go_router/go_router.dart';
+
+import '../backend/backend.dart';
+import '../features/collections/presentation/collection_details_screen.dart';
+import '../features/collections/presentation/collections_screen.dart';
+import '../features/favorites/presentation/favorites_screen.dart';
+import '../features/feed/presentation/feed_screen.dart';
+import '../features/post/presentation/post_details_screen.dart';
+import '../features/providers/presentation/provider_check_screen.dart';
+import '../features/providers/presentation/provider_form_screen.dart';
+import '../features/providers/presentation/providers_screen.dart';
+import '../features/search/presentation/search_screen.dart';
+import '../features/settings/presentation/settings_screen.dart';
+import '../shared/widgets/app_shell.dart';
+
+final appRouterProvider = Provider<GoRouter>((ref) {
+  return GoRouter(
+    initialLocation: '/',
+    routes: [
+      ShellRoute(
+        builder: (context, state, child) => AppShell(child: child),
+        routes: [
+          GoRoute(
+            path: '/',
+            pageBuilder: (context, state) => NoTransitionPage(
+              child: FeedScreen(initialQuery: state.uri.queryParameters['q']),
+            ),
+          ),
+          GoRoute(
+            path: '/search',
+            builder: (context, state) => const SearchScreen(),
+          ),
+          GoRoute(
+            path: '/post/:providerId/:postId',
+            builder: (context, state) => PostDetailsScreen(
+              providerId: state.pathParameters['providerId']!,
+              postId: state.pathParameters['postId']!,
+              initialPost: state.extra is Post ? state.extra! as Post : null,
+            ),
+          ),
+          GoRoute(
+            path: '/favorites',
+            builder: (context, state) => const FavoritesScreen(),
+          ),
+          GoRoute(
+            path: '/collections',
+            builder: (context, state) => const CollectionsScreen(),
+          ),
+          GoRoute(
+            path: '/collections/:collectionId',
+            builder: (context, state) => CollectionDetailsScreen(
+              collectionId: state.pathParameters['collectionId']!,
+            ),
+          ),
+          GoRoute(
+            path: '/providers',
+            builder: (context, state) => const ProvidersScreen(),
+          ),
+          GoRoute(
+            path: '/providers/new',
+            builder: (context, state) => ProviderFormScreen(
+              initialConfig: state.extra is ContentProviderConfig
+                  ? state.extra! as ContentProviderConfig
+                  : null,
+            ),
+          ),
+          GoRoute(
+            path: '/providers/check',
+            builder: (context, state) => const ProviderCheckScreen(),
+          ),
+          GoRoute(
+            path: '/settings',
+            builder: (context, state) => const SettingsScreen(),
+          ),
+        ],
+      ),
+    ],
+  );
+});

lib/app/theme.dart

@@ -0,0 +1,46 @@
+import 'package:flutter/material.dart';
+
+ThemeData buildTheme(Brightness brightness) {
+  final dark = brightness == Brightness.dark;
+  final scheme = ColorScheme.fromSeed(
+    seedColor: const Color(0xFFE84D8A),
+    brightness: brightness,
+  );
+  return ThemeData(
+    useMaterial3: true,
+    brightness: brightness,
+    colorScheme: scheme,
+    scaffoldBackgroundColor:
+        dark ? const Color(0xFF101114) : const Color(0xFFF8F8FA),
+    cardColor: dark ? const Color(0xFF191B20) : Colors.white,
+    navigationRailTheme: NavigationRailThemeData(
+      backgroundColor: dark ? const Color(0xFF15161A) : Colors.white,
+      selectedIconTheme: IconThemeData(color: scheme.primary),
+    ),
+    appBarTheme: AppBarTheme(
+      centerTitle: false,
+      elevation: 0,
+      backgroundColor: dark ? const Color(0xFF101114) : const Color(0xFFF8F8FA),
+      foregroundColor: scheme.onSurface,
+    ),
+    cardTheme: CardThemeData(
+      elevation: 0,
+      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(8)),
+    ),
+    inputDecorationTheme: InputDecorationTheme(
+      filled: true,
+      border: OutlineInputBorder(
+        borderRadius: BorderRadius.circular(8),
+        borderSide: BorderSide.none,
+      ),
+    ),
+  );
+}
+
+ThemeMode parseThemeMode(String value) {
+  return switch (value) {
+    'light' => ThemeMode.light,
+    'system' => ThemeMode.system,
+    _ => ThemeMode.dark,
+  };
+}

lib/backend/backend.dart

@@ -0,0 +1,16 @@
+export 'di/backend_providers.dart';
+export 'models/collection.dart';
+export 'models/content_provider_config.dart';
+export 'models/favorite.dart';
+export 'models/post.dart';
+export 'models/provider_health.dart';
+export 'models/search_history.dart';
+export 'models/top_period_filter.dart';
+export 'providers/content_provider.dart';
+export 'providers/provider_manager.dart';
+export 'services/collection_service.dart';
+export 'services/favorite_service.dart';
+export 'services/feed_service.dart';
+export 'services/provider_check_service.dart';
+export 'services/search_service.dart';
+export 'services/settings_service.dart';

lib/backend/di/backend_providers.dart

@@ -0,0 +1,121 @@
+import 'package:connectivity_plus/connectivity_plus.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+import '../../core/cache/cache_service.dart';
+import '../../core/cache/image_cache_service.dart';
+import '../../core/database/app_database.dart';
+import '../../core/database/database_service.dart';
+import '../../core/http/network_info.dart';
+import '../providers/provider_factory.dart';
+import '../providers/provider_manager.dart';
+import '../repositories/collection_repository.dart';
+import '../repositories/favorite_repository.dart';
+import '../repositories/post_repository.dart';
+import '../repositories/provider_repository.dart';
+import '../repositories/search_repository.dart';
+import '../services/collection_service.dart';
+import '../services/favorite_service.dart';
+import '../services/feed_service.dart';
+import '../services/provider_check_service.dart';
+import '../services/search_service.dart';
+import '../services/settings_service.dart';
+
+final appDatabaseProvider = FutureProvider<AppDatabase>((ref) async {
+  final database = await AppDatabase.open();
+  ref.onDispose(database.close);
+  return database;
+});
+
+final databaseServiceProvider = Provider<DatabaseService>((ref) {
+  final database = ref.watch(appDatabaseProvider).requireValue;
+  return DatabaseService(database);
+});
+
+final connectivityProvider = Provider<Connectivity>((ref) => Connectivity());
+
+final networkInfoProvider = Provider<NetworkInfo>((ref) {
+  return NetworkInfo(ref.watch(connectivityProvider));
+});
+
+final providerFactoryProvider = Provider<ProviderFactory>((ref) {
+  return ProviderFactory();
+});
+
+final postRepositoryProvider = Provider<PostRepository>((ref) {
+  return PostRepository(ref.watch(databaseServiceProvider));
+});
+
+final providerRepositoryProvider = Provider<ProviderRepository>((ref) {
+  return ProviderRepository(ref.watch(databaseServiceProvider));
+});
+
+final searchRepositoryProvider = Provider<SearchRepository>((ref) {
+  return SearchRepository(ref.watch(databaseServiceProvider));
+});
+
+final favoriteRepositoryProvider = Provider<FavoriteRepository>((ref) {
+  return FavoriteRepository(
+    ref.watch(databaseServiceProvider),
+    ref.watch(postRepositoryProvider),
+  );
+});
+
+final collectionRepositoryProvider = Provider<CollectionRepository>((ref) {
+  return CollectionRepository(
+    ref.watch(databaseServiceProvider),
+    ref.watch(postRepositoryProvider),
+  );
+});
+
+final cacheServiceProvider = Provider<CacheService>((ref) {
+  return CacheService(ref.watch(databaseServiceProvider));
+});
+
+final imageCacheServiceProvider = Provider<ImageCacheService>((ref) {
+  return ImageCacheService();
+});
+
+final providerManagerProvider = Provider<ProviderManager>((ref) {
+  return ProviderManager(
+    ref.watch(providerRepositoryProvider),
+    ref.watch(providerFactoryProvider),
+  );
+});
+
+final feedServiceProvider = Provider<FeedService>((ref) {
+  return FeedService(
+    ref.watch(providerManagerProvider),
+    ref.watch(cacheServiceProvider),
+    ref.watch(settingsServiceProvider),
+  );
+});
+
+final searchServiceProvider = Provider<SearchService>((ref) {
+  return SearchService(ref.watch(searchRepositoryProvider));
+});
+
+final providerCheckServiceProvider = Provider<ProviderCheckService>((ref) {
+  return ProviderCheckService(
+    ref.watch(providerRepositoryProvider),
+    ref.watch(providerFactoryProvider),
+    ref.watch(providerManagerProvider),
+  );
+});
+
+final favoriteServiceProvider = Provider<FavoriteService>((ref) {
+  return FavoriteService(
+    ref.watch(favoriteRepositoryProvider),
+    ref.watch(postRepositoryProvider),
+  );
+});
+
+final collectionServiceProvider = Provider<CollectionService>((ref) {
+  return CollectionService(ref.watch(collectionRepositoryProvider));
+});
+
+final settingsServiceProvider = Provider<SettingsService>((ref) {
+  return SettingsService(
+    ref.watch(databaseServiceProvider),
+    providerRepository: ref.watch(providerRepositoryProvider),
+  );
+});

lib/backend/mappers/danbooru_mapper.dart

@@ -0,0 +1,80 @@
+import '../models/post.dart';
+
+class DanbooruMapper {
+  static List<Post> postsFromResponse(
+    dynamic data, {
+    required String providerId,
+    required String providerName,
+  }) {
+    final items = data is List ? data : const [];
+    return items
+        .whereType<Map>()
+        .map((item) => postFromJson(
+              Map<String, dynamic>.from(item),
+              providerId: providerId,
+              providerName: providerName,
+            ))
+        .toList();
+  }
+
+  static Post postFromJson(
+    Map<String, dynamic> json, {
+    required String providerId,
+    required String providerName,
+  }) {
+    final fileUrl = _string(json['file_url'] ?? json['large_file_url']);
+    final sampleUrl =
+        _string(json['large_file_url'] ?? json['sample_file_url'] ?? fileUrl);
+    final previewUrl = _string(json['preview_file_url'] ?? sampleUrl);
+    return Post(
+      id: _string(json['id']),
+      providerId: providerId,
+      providerName: providerName,
+      previewUrl: previewUrl,
+      sampleUrl: sampleUrl,
+      fileUrl: fileUrl,
+      tags: _tags(json['tag_string'] ?? json['tags']),
+      rating: _string(json['rating'], fallback: 'unknown'),
+      width: _int(json['image_width'] ?? json['width']),
+      height: _int(json['image_height'] ?? json['height']),
+      source: _nullableString(json['source']),
+      createdAt:
+          DateTime.tryParse(_string(json['created_at'])) ?? DateTime.now(),
+      fileType: _fileType(fileUrl),
+      score: _int(json['score']),
+    );
+  }
+
+  static List<String> _tags(dynamic value) {
+    if (value is List) return value.map((tag) => tag.toString()).toList();
+    return _string(value)
+        .split(RegExp(r'\s+'))
+        .where((tag) => tag.trim().isNotEmpty)
+        .toSet()
+        .toList();
+  }
+
+  static int _int(dynamic value) {
+    if (value is int) return value;
+    if (value is num) return value.toInt();
+    return int.tryParse(value?.toString() ?? '') ?? 0;
+  }
+
+  static String _string(dynamic value, {String fallback = ''}) {
+    final text = value?.toString();
+    return text == null || text.isEmpty ? fallback : text;
+  }
+
+  static String? _nullableString(dynamic value) {
+    final text = value?.toString();
+    return text == null || text.isEmpty ? null : text;
+  }
+
+  static String _fileType(String url) {
+    final lower = url.toLowerCase();
+    if (lower.endsWith('.webm') || lower.endsWith('.mp4')) return 'video';
+    if (lower.endsWith('.gif')) return 'gif';
+    if (lower.isEmpty) return 'unknown';
+    return 'image';
+  }
+}

lib/backend/mappers/gelbooru_mapper.dart

@@ -0,0 +1,99 @@
+import '../models/post.dart';
+
+class GelbooruMapper {
+  static List<Post> postsFromResponse(
+    dynamic data, {
+    required String providerId,
+    required String providerName,
+  }) {
+    final items = _extractItems(data);
+    return items
+        .whereType<Map>()
+        .map((item) => postFromJson(
+              Map<String, dynamic>.from(item),
+              providerId: providerId,
+              providerName: providerName,
+            ))
+        .toList();
+  }
+
+  static Post postFromJson(
+    Map<String, dynamic> json, {
+    required String providerId,
+    required String providerName,
+  }) {
+    final id = _string(json['id']);
+    final fileUrl = _string(json['file_url'] ?? json['fileUrl']);
+    final sampleUrl = _string(json['sample_url'] ??
+        json['sampleUrl'] ??
+        json['large_file_url'] ??
+        fileUrl);
+    final previewUrl =
+        _string(json['preview_url'] ?? json['previewUrl'] ?? sampleUrl);
+    return Post(
+      id: id,
+      providerId: providerId,
+      providerName: providerName,
+      previewUrl: previewUrl,
+      sampleUrl: sampleUrl,
+      fileUrl: fileUrl,
+      tags: _tags(json['tags'] ?? json['tag_string']),
+      rating: _string(json['rating'], fallback: 'unknown'),
+      width: _int(json['width']),
+      height: _int(json['height']),
+      source: _nullableString(json['source']),
+      createdAt: _date(json['created_at'] ?? json['createdAt']),
+      fileType: _fileType(fileUrl),
+      score: _int(json['score']),
+    );
+  }
+
+  static List<dynamic> _extractItems(dynamic data) {
+    if (data is List) return data;
+    if (data is Map) {
+      final posts = data['post'] ?? data['posts'];
+      if (posts is List) return posts;
+      if (posts is Map && posts['post'] is List) return posts['post'] as List;
+      if (posts is Map) return [posts];
+    }
+    return const [];
+  }
+
+  static List<String> _tags(dynamic value) {
+    if (value is List) return value.map((tag) => tag.toString()).toList();
+    return _string(value)
+        .split(RegExp(r'\s+'))
+        .where((tag) => tag.trim().isNotEmpty)
+        .toSet()
+        .toList();
+  }
+
+  static int _int(dynamic value) {
+    if (value is int) return value;
+    if (value is num) return value.toInt();
+    return int.tryParse(value?.toString() ?? '') ?? 0;
+  }
+
+  static String _string(dynamic value, {String fallback = ''}) {
+    final text = value?.toString();
+    return text == null || text.isEmpty ? fallback : text;
+  }
+
+  static String? _nullableString(dynamic value) {
+    final text = value?.toString();
+    return text == null || text.isEmpty ? null : text;
+  }
+
+  static DateTime _date(dynamic value) {
+    if (value is int) return DateTime.fromMillisecondsSinceEpoch(value * 1000);
+    return DateTime.tryParse(value?.toString() ?? '') ?? DateTime.now();
+  }
+
+  static String _fileType(String url) {
+    final lower = url.toLowerCase();
+    if (lower.endsWith('.webm') || lower.endsWith('.mp4')) return 'video';
+    if (lower.endsWith('.gif')) return 'gif';
+    if (lower.isEmpty) return 'unknown';
+    return 'image';
+  }
+}

lib/backend/mappers/rule34_mapper.dart

@@ -0,0 +1,16 @@
+import '../models/post.dart';
+import 'gelbooru_mapper.dart';
+
+class Rule34Mapper {
+  static List<Post> postsFromResponse(
+    dynamic data, {
+    required String providerId,
+    required String providerName,
+  }) {
+    return GelbooruMapper.postsFromResponse(
+      data,
+      providerId: providerId,
+      providerName: providerName,
+    );
+  }
+}

lib/backend/models/collection.dart

@@ -0,0 +1,34 @@
+class Collection {
+  const Collection({
+    required this.id,
+    required this.name,
+    this.description,
+    this.coverUrl,
+    required this.createdAt,
+    required this.updatedAt,
+  });
+
+  final String id;
+  final String name;
+  final String? description;
+  final String? coverUrl;
+  final DateTime createdAt;
+  final DateTime updatedAt;
+
+  Collection copyWith({
+    String? id,
+    String? name,
+    String? description,
+    String? coverUrl,
+    DateTime? createdAt,
+    DateTime? updatedAt,
+  }) =>
+      Collection(
+        id: id ?? this.id,
+        name: name ?? this.name,
+        description: description ?? this.description,
+        coverUrl: coverUrl ?? this.coverUrl,
+        createdAt: createdAt ?? this.createdAt,
+        updatedAt: updatedAt ?? this.updatedAt,
+      );
+}

lib/backend/models/content_provider_config.dart

@@ -0,0 +1,81 @@
+class ContentProviderConfig {
+  const ContentProviderConfig({
+    required this.id,
+    required this.name,
+    required this.baseUrl,
+    required this.apiType,
+    required this.enabled,
+    required this.priority,
+    required this.timeoutSeconds,
+    required this.customHeaders,
+    required this.createdAt,
+    required this.updatedAt,
+  });
+
+  final String id;
+  final String name;
+  final String baseUrl;
+  final String apiType;
+  final bool enabled;
+  final int priority;
+  final int timeoutSeconds;
+  final Map<String, String> customHeaders;
+  final DateTime createdAt;
+  final DateTime updatedAt;
+
+  ContentProviderConfig copyWith({
+    String? id,
+    String? name,
+    String? baseUrl,
+    String? apiType,
+    bool? enabled,
+    int? priority,
+    int? timeoutSeconds,
+    Map<String, String>? customHeaders,
+    DateTime? createdAt,
+    DateTime? updatedAt,
+  }) {
+    return ContentProviderConfig(
+      id: id ?? this.id,
+      name: name ?? this.name,
+      baseUrl: baseUrl ?? this.baseUrl,
+      apiType: apiType ?? this.apiType,
+      enabled: enabled ?? this.enabled,
+      priority: priority ?? this.priority,
+      timeoutSeconds: timeoutSeconds ?? this.timeoutSeconds,
+      customHeaders: customHeaders ?? this.customHeaders,
+      createdAt: createdAt ?? this.createdAt,
+      updatedAt: updatedAt ?? this.updatedAt,
+    );
+  }
+
+  Map<String, dynamic> toJson() => {
+        'id': id,
+        'name': name,
+        'baseUrl': baseUrl,
+        'apiType': apiType,
+        'enabled': enabled,
+        'priority': priority,
+        'timeoutSeconds': timeoutSeconds,
+        'customHeaders': customHeaders,
+        'createdAt': createdAt.toIso8601String(),
+        'updatedAt': updatedAt.toIso8601String(),
+      };
+
+  factory ContentProviderConfig.fromJson(Map<String, dynamic> json) {
+    return ContentProviderConfig(
+      id: json['id'] as String,
+      name: json['name'] as String,
+      baseUrl: json['baseUrl'] as String,
+      apiType: json['apiType'] as String,
+      enabled: (json['enabled'] as bool?) ?? true,
+      priority: (json['priority'] as num?)?.toInt() ?? 0,
+      timeoutSeconds: (json['timeoutSeconds'] as num?)?.toInt() ?? 20,
+      customHeaders: Map<String, String>.from(
+        (json['customHeaders'] as Map?) ?? const {},
+      ),
+      createdAt: DateTime.parse(json['createdAt'] as String),
+      updatedAt: DateTime.parse(json['updatedAt'] as String),
+    );
+  }
+}

lib/backend/models/favorite.dart

@@ -0,0 +1,13 @@
+class Favorite {
+  const Favorite({
+    required this.id,
+    required this.postId,
+    required this.providerId,
+    required this.savedAt,
+  });
+
+  final String id;
+  final String postId;
+  final String providerId;
+  final DateTime savedAt;
+}

lib/backend/models/post.dart

@@ -0,0 +1,70 @@
+class Post {
+  const Post({
+    required this.id,
+    required this.providerId,
+    required this.providerName,
+    required this.previewUrl,
+    required this.sampleUrl,
+    required this.fileUrl,
+    required this.tags,
+    required this.rating,
+    required this.width,
+    required this.height,
+    this.source,
+    required this.createdAt,
+    required this.fileType,
+    required this.score,
+  });
+
+  final String id;
+  final String providerId;
+  final String providerName;
+  final String previewUrl;
+  final String sampleUrl;
+  final String fileUrl;
+  final List<String> tags;
+  final String rating;
+  final int width;
+  final int height;
+  final String? source;
+  final DateTime createdAt;
+  final String fileType;
+  final int score;
+
+  String get cacheKey => '$providerId:$id';
+
+  Map<String, dynamic> toJson() => {
+        'id': id,
+        'providerId': providerId,
+        'providerName': providerName,
+        'previewUrl': previewUrl,
+        'sampleUrl': sampleUrl,
+        'fileUrl': fileUrl,
+        'tags': tags,
+        'rating': rating,
+        'width': width,
+        'height': height,
+        'source': source,
+        'createdAt': createdAt.toIso8601String(),
+        'fileType': fileType,
+        'score': score,
+      };
+
+  factory Post.fromJson(Map<String, dynamic> json) => Post(
+        id: json['id'].toString(),
+        providerId: json['providerId'] as String,
+        providerName: json['providerName'] as String,
+        previewUrl: (json['previewUrl'] as String?) ?? '',
+        sampleUrl: (json['sampleUrl'] as String?) ?? '',
+        fileUrl: (json['fileUrl'] as String?) ?? '',
+        tags: List<String>.from((json['tags'] as List?) ?? const []),
+        rating: (json['rating'] as String?) ?? 'unknown',
+        width: (json['width'] as num?)?.toInt() ?? 0,
+        height: (json['height'] as num?)?.toInt() ?? 0,
+        source: json['source'] as String?,
+        createdAt: DateTime.tryParse((json['createdAt'] as String?) ?? '') ??
+            DateTime.fromMillisecondsSinceEpoch(0),
+        fileType: (json['fileType'] as String?) ?? 'unknown',
+        score: (json['score'] as num?)?.toInt() ?? 0,
+      );
+}

lib/backend/models/provider_health.dart

@@ -0,0 +1,42 @@
+enum ProviderStatus { unknown, online, offline }
+
+class ProviderHealth {
+  const ProviderHealth({
+    required this.providerId,
+    required this.status,
+    required this.pingMs,
+    required this.lastCheckedAt,
+    this.errorMessage,
+    this.apiVersion,
+  });
+
+  final String providerId;
+  final ProviderStatus status;
+  final int pingMs;
+  final DateTime lastCheckedAt;
+  final String? errorMessage;
+  final String? apiVersion;
+
+  bool get isOnline => status == ProviderStatus.online;
+
+  Map<String, dynamic> toJson() => {
+        'providerId': providerId,
+        'status': status.name,
+        'pingMs': pingMs,
+        'lastCheckedAt': lastCheckedAt.toIso8601String(),
+        'errorMessage': errorMessage,
+        'apiVersion': apiVersion,
+      };
+
+  factory ProviderHealth.fromJson(Map<String, dynamic> json) => ProviderHealth(
+        providerId: json['providerId'] as String,
+        status: ProviderStatus.values.firstWhere(
+          (value) => value.name == json['status'],
+          orElse: () => ProviderStatus.unknown,
+        ),
+        pingMs: (json['pingMs'] as num?)?.toInt() ?? 0,
+        lastCheckedAt: DateTime.parse(json['lastCheckedAt'] as String),
+        errorMessage: json['errorMessage'] as String?,
+        apiVersion: json['apiVersion'] as String?,
+      );
+}

lib/backend/models/search_history.dart

@@ -0,0 +1,15 @@
+class SearchHistory {
+  const SearchHistory({
+    required this.id,
+    required this.query,
+    required this.tags,
+    required this.searchedAt,
+    required this.resultCount,
+  });
+
+  final String id;
+  final String query;
+  final List<String> tags;
+  final DateTime searchedAt;
+  final int resultCount;
+}

lib/backend/models/top_period_filter.dart

@@ -0,0 +1,15 @@
+enum TopPeriodFilter {
+  none,
+  month,
+  year,
+  allTime;
+
+  String get label {
+    return switch (this) {
+      TopPeriodFilter.none => 'Latest',
+      TopPeriodFilter.month => 'Top month',
+      TopPeriodFilter.year => 'Top year',
+      TopPeriodFilter.allTime => 'Top all time',
+    };
+  }
+}

lib/backend/providers/content_provider.dart

@@ -0,0 +1,21 @@
+import '../models/post.dart';
+import '../models/provider_health.dart';
+import '../models/top_period_filter.dart';
+
+abstract class ContentProvider {
+  String get id;
+  String get name;
+  String get baseUrl;
+
+  Future<List<Post>> searchPosts({
+    required List<String> tags,
+    required int page,
+    int limit = 50,
+    String? rating,
+    TopPeriodFilter topPeriod = TopPeriodFilter.none,
+  });
+
+  Future<Post?> getPost(String id);
+
+  Future<ProviderHealth> checkHealth();
+}

lib/backend/providers/custom_provider.dart

@@ -0,0 +1,84 @@
+import '../../core/errors/app_exception.dart';
+import '../models/post.dart';
+import '../models/provider_health.dart';
+import '../models/top_period_filter.dart';
+import 'content_provider.dart';
+
+class CustomProvider implements ContentProvider {
+  CustomProvider(this._delegate);
+
+  final ContentProvider _delegate;
+
+  @override
+  String get id => _delegate.id;
+  @override
+  String get name => _delegate.name;
+  @override
+  String get baseUrl => _delegate.baseUrl;
+
+  @override
+  Future<List<Post>> searchPosts({
+    required List<String> tags,
+    required int page,
+    int limit = 50,
+    String? rating,
+    TopPeriodFilter topPeriod = TopPeriodFilter.none,
+  }) =>
+      _delegate.searchPosts(
+        tags: tags,
+        page: page,
+        limit: limit,
+        rating: rating,
+        topPeriod: topPeriod,
+      );
+
+  @override
+  Future<Post?> getPost(String id) => _delegate.getPost(id);
+
+  @override
+  Future<ProviderHealth> checkHealth() => _delegate.checkHealth();
+}
+
+class UnsupportedCustomProvider implements ContentProvider {
+  UnsupportedCustomProvider({
+    required this.id,
+    required this.name,
+    required this.baseUrl,
+    required this.apiType,
+  });
+
+  @override
+  final String id;
+  @override
+  final String name;
+  @override
+  final String baseUrl;
+  final String apiType;
+
+  @override
+  Future<List<Post>> searchPosts({
+    required List<String> tags,
+    required int page,
+    int limit = 50,
+    String? rating,
+    TopPeriodFilter topPeriod = TopPeriodFilter.none,
+  }) async {
+    throw ProviderUnavailableException(
+        'Unsupported provider apiType: $apiType');
+  }
+
+  @override
+  Future<Post?> getPost(String id) async {
+    throw ProviderUnavailableException(
+        'Unsupported provider apiType: $apiType');
+  }
+
+  @override
+  Future<ProviderHealth> checkHealth() async => ProviderHealth(
+        providerId: id,
+        status: ProviderStatus.offline,
+        pingMs: 0,
+        lastCheckedAt: DateTime.now(),
+        errorMessage: 'Unsupported provider apiType: $apiType',
+      );
+}

lib/backend/providers/danbooru_provider.dart

@@ -0,0 +1,106 @@
+import 'package:dio/dio.dart';
+
+import '../../core/http/dio_client.dart';
+import '../mappers/danbooru_mapper.dart';
+import '../models/post.dart';
+import '../models/provider_health.dart';
+import '../models/top_period_filter.dart';
+import 'content_provider.dart';
+
+class DanbooruProvider implements ContentProvider {
+  DanbooruProvider({
+    required this.id,
+    required this.name,
+    required this.baseUrl,
+    required DioClient dioClient,
+    Map<String, String> queryParameters = const {},
+  })  : _queryParameters = queryParameters,
+        _dio = dioClient.dio;
+
+  @override
+  final String id;
+  @override
+  final String name;
+  @override
+  final String baseUrl;
+  final Dio _dio;
+  final Map<String, String> _queryParameters;
+
+  @override
+  Future<List<Post>> searchPosts({
+    required List<String> tags,
+    required int page,
+    int limit = 50,
+    String? rating,
+    TopPeriodFilter topPeriod = TopPeriodFilter.none,
+  }) async {
+    final queryTags = [
+      ...tags,
+      if (rating != null && rating.isNotEmpty) 'rating:$rating',
+      ..._topTags(topPeriod),
+    ];
+    final response = await _dio.get<dynamic>(
+      '/posts.json',
+      queryParameters: {
+        'page': page <= 0 ? 1 : page,
+        'limit': limit,
+        'tags': queryTags.join(' '),
+        ..._queryParameters,
+      },
+    );
+    return DanbooruMapper.postsFromResponse(
+      response.data,
+      providerId: id,
+      providerName: name,
+    );
+  }
+
+  @override
+  Future<Post?> getPost(String id) async {
+    final response = await _dio.get<dynamic>(
+      '/posts/$id.json',
+      queryParameters: _queryParameters,
+    );
+    final posts = DanbooruMapper.postsFromResponse(
+      [response.data],
+      providerId: this.id,
+      providerName: name,
+    );
+    return posts.isEmpty ? null : posts.first;
+  }
+
+  @override
+  Future<ProviderHealth> checkHealth() async {
+    final startedAt = DateTime.now();
+    try {
+      await _dio.get<dynamic>(
+        '/posts.json',
+        queryParameters: {'limit': 1, ..._queryParameters},
+      );
+      return ProviderHealth(
+        providerId: id,
+        status: ProviderStatus.online,
+        pingMs: DateTime.now().difference(startedAt).inMilliseconds,
+        lastCheckedAt: DateTime.now(),
+        apiVersion: 'danbooru',
+      );
+    } catch (error) {
+      return ProviderHealth(
+        providerId: id,
+        status: ProviderStatus.offline,
+        pingMs: DateTime.now().difference(startedAt).inMilliseconds,
+        lastCheckedAt: DateTime.now(),
+        errorMessage: error.toString(),
+        apiVersion: 'danbooru',
+      );
+    }
+  }
+
+  List<String> _topTags(TopPeriodFilter period) {
+    return switch (period) {
+      TopPeriodFilter.none => const [],
+      TopPeriodFilter.month || TopPeriodFilter.year => const ['order:rank'],
+      TopPeriodFilter.allTime => const ['order:score'],
+    };
+  }
+}

lib/backend/providers/gelbooru_provider.dart

@@ -0,0 +1,132 @@
+import 'package:dio/dio.dart';
+
+import '../../core/errors/app_exception.dart';
+import '../../core/http/dio_client.dart';
+import '../mappers/gelbooru_mapper.dart';
+import '../models/post.dart';
+import '../models/provider_health.dart';
+import '../models/top_period_filter.dart';
+import 'content_provider.dart';
+
+class GelbooruProvider implements ContentProvider {
+  GelbooruProvider({
+    required this.id,
+    required this.name,
+    required this.baseUrl,
+    required DioClient dioClient,
+    Map<String, String> queryParameters = const {},
+  })  : _queryParameters = queryParameters,
+        _dio = dioClient.dio;
+
+  @override
+  final String id;
+  @override
+  final String name;
+  @override
+  final String baseUrl;
+  final Dio _dio;
+  final Map<String, String> _queryParameters;
+  Dio get dio => _dio;
+  Map<String, String> get queryParameters => _queryParameters;
+
+  @override
+  Future<List<Post>> searchPosts({
+    required List<String> tags,
+    required int page,
+    int limit = 50,
+    String? rating,
+    TopPeriodFilter topPeriod = TopPeriodFilter.none,
+  }) async {
+    final queryTags = [
+      ...tags,
+      if (rating != null && rating.isNotEmpty) 'rating:$rating',
+      ..._topTags(topPeriod),
+    ];
+    final response = await _dio.get<dynamic>(
+      '/index.php',
+      queryParameters: {
+        'page': 'dapi',
+        's': 'post',
+        'q': 'index',
+        'json': '1',
+        'pid': page,
+        'limit': limit,
+        'tags': queryTags.join(' '),
+        ..._queryParameters,
+      },
+    );
+    return GelbooruMapper.postsFromResponse(
+      response.data,
+      providerId: id,
+      providerName: name,
+    );
+  }
+
+  @override
+  Future<Post?> getPost(String id) async {
+    final response = await _dio.get<dynamic>(
+      '/index.php',
+      queryParameters: {
+        'page': 'dapi',
+        's': 'post',
+        'q': 'index',
+        'json': '1',
+        'id': id,
+        ..._queryParameters,
+      },
+    );
+    final posts = GelbooruMapper.postsFromResponse(
+      response.data,
+      providerId: this.id,
+      providerName: name,
+    );
+    return posts.isEmpty ? null : posts.first;
+  }
+
+  @override
+  Future<ProviderHealth> checkHealth() async {
+    final startedAt = DateTime.now();
+    try {
+      await _dio.get<dynamic>(
+        '/index.php',
+        queryParameters: {
+          'page': 'dapi',
+          's': 'post',
+          'q': 'index',
+          'json': '1',
+          'limit': 1,
+          ..._queryParameters,
+        },
+      );
+      return ProviderHealth(
+        providerId: id,
+        status: ProviderStatus.online,
+        pingMs: DateTime.now().difference(startedAt).inMilliseconds,
+        lastCheckedAt: DateTime.now(),
+        apiVersion: 'gelbooru-compatible',
+      );
+    } catch (error) {
+      return ProviderHealth(
+        providerId: id,
+        status: ProviderStatus.offline,
+        pingMs: DateTime.now().difference(startedAt).inMilliseconds,
+        lastCheckedAt: DateTime.now(),
+        errorMessage: error.toString(),
+        apiVersion: 'gelbooru-compatible',
+      );
+    }
+  }
+
+  Never unavailable(String message) =>
+      throw ProviderUnavailableException(message);
+
+  List<String> _topTags(TopPeriodFilter period) {
+    return switch (period) {
+      TopPeriodFilter.none => const [],
+      TopPeriodFilter.month ||
+      TopPeriodFilter.year ||
+      TopPeriodFilter.allTime =>
+        const ['sort:score:desc'],
+    };
+  }
+}

lib/backend/providers/provider_factory.dart

@@ -0,0 +1,53 @@
+import '../../core/http/dio_client.dart';
+import '../models/content_provider_config.dart';
+import 'content_provider.dart';
+import 'custom_provider.dart';
+import 'danbooru_provider.dart';
+import 'gelbooru_provider.dart';
+import 'rule34_provider.dart';
+
+class ProviderFactory {
+  ContentProvider create(ContentProviderConfig config) {
+    final headers = Map<String, String>.from(config.customHeaders)
+      ..removeWhere((key, _) => key.startsWith('query.'));
+    final queryParameters = {
+      for (final entry in config.customHeaders.entries)
+        if (entry.key.startsWith('query.') && entry.value.trim().isNotEmpty)
+          entry.key.substring('query.'.length): entry.value.trim(),
+    };
+    final client = DioClient(
+      baseUrl: config.baseUrl,
+      timeout: Duration(seconds: config.timeoutSeconds),
+      headers: headers,
+    );
+    return switch (config.apiType.toLowerCase()) {
+      'gelbooru' => GelbooruProvider(
+          id: config.id,
+          name: config.name,
+          baseUrl: config.baseUrl,
+          dioClient: client,
+          queryParameters: queryParameters,
+        ),
+      'rule34' => Rule34Provider(
+          id: config.id,
+          name: config.name,
+          baseUrl: config.baseUrl,
+          dioClient: client,
+          queryParameters: queryParameters,
+        ),
+      'danbooru' => DanbooruProvider(
+          id: config.id,
+          name: config.name,
+          baseUrl: config.baseUrl,
+          dioClient: client,
+          queryParameters: queryParameters,
+        ),
+      _ => UnsupportedCustomProvider(
+          id: config.id,
+          name: config.name,
+          baseUrl: config.baseUrl,
+          apiType: config.apiType,
+        ),
+    };
+  }
+}

lib/backend/providers/provider_manager.dart

@@ -0,0 +1,172 @@
+import 'dart:async';
+
+import '../../core/errors/failure.dart';
+import '../../core/utils/result.dart';
+import '../models/content_provider_config.dart';
+import '../models/post.dart';
+import '../models/provider_health.dart';
+import '../models/top_period_filter.dart';
+import '../repositories/provider_repository.dart';
+import 'content_provider.dart';
+import 'provider_factory.dart';
+
+class ProviderManager {
+  ProviderManager(this._repository, this._factory);
+
+  final ProviderRepository _repository;
+  final ProviderFactory _factory;
+
+  Future<Result<List<ContentProviderConfig>>> loadConfigs({
+    bool enabledOnly = true,
+  }) async {
+    await _repository.ensureSeedProviders();
+    return _repository.getProviders(enabledOnly: enabledOnly);
+  }
+
+  Future<Result<List<ContentProvider>>> activeProviders() async {
+    final result = await loadConfigs();
+    if (result is Error<List<ContentProviderConfig>>) {
+      return Error(result.failure);
+    }
+    final configs = (result as Success<List<ContentProviderConfig>>).data
+      ..sort((a, b) => a.priority.compareTo(b.priority));
+    return Success(configs.map(_factory.create).toList());
+  }
+
+  Future<Result<void>> enableProvider(String id, bool enabled) async {
+    final result = await _repository.getProvider(id);
+    return result.fold(
+      onSuccess: (config) {
+        if (config == null) {
+          return const Error<void>(
+            Failure(code: 'not_found', message: 'Provider not found'),
+          );
+        }
+        return _repository.saveProvider(
+          config.copyWith(enabled: enabled, updatedAt: DateTime.now()),
+        );
+      },
+      onError: Error<void>.new,
+    );
+  }
+
+  Future<Result<void>> addCustomProvider(ContentProviderConfig config) {
+    return _repository.saveProvider(config.copyWith(updatedAt: DateTime.now()));
+  }
+
+  Future<Result<void>> deleteProvider(String id) =>
+      _repository.deleteProvider(id);
+
+  Future<Result<List<ProviderHealth>>> checkAll({int concurrency = 3}) async {
+    final providersResult = await activeProviders();
+    if (providersResult is Error<List<ContentProvider>>) {
+      return Error(providersResult.failure);
+    }
+    final providers = (providersResult as Success<List<ContentProvider>>).data;
+    if (providers.isEmpty) return const Success([]);
+    final results = await _runLimited(
+      providers,
+      concurrency,
+      (provider) async {
+        final health = await provider.checkHealth();
+        await _repository.saveHealth(health);
+        return health;
+      },
+    );
+    return Success(results);
+  }
+
+  Future<Result<List<Post>>> searchAcrossProviders({
+    required List<String> tags,
+    required int page,
+    int limit = 50,
+    String? rating,
+    String? providerId,
+    TopPeriodFilter topPeriod = TopPeriodFilter.none,
+  }) async {
+    final providersResult = await activeProviders();
+    if (providersResult is Error<List<ContentProvider>>) {
+      return Error(providersResult.failure);
+    }
+    var providers = (providersResult as Success<List<ContentProvider>>).data;
+    if (providerId != null) {
+      providers =
+          providers.where((provider) => provider.id == providerId).toList();
+    }
+
+    final posts = <Post>[];
+    for (final provider in providers) {
+      final health = await _repository.getHealth(provider.id);
+      final offline = health is Success<ProviderHealth?> &&
+          health.data?.status == ProviderStatus.offline;
+      if (offline) continue;
+
+      try {
+        final providerPosts = await provider.searchPosts(
+          tags: tags,
+          page: page,
+          limit: limit,
+          rating: rating,
+          topPeriod: topPeriod,
+        );
+        posts.addAll(providerPosts);
+      } catch (_) {
+        await _repository.saveHealth(
+          ProviderHealth(
+            providerId: provider.id,
+            status: ProviderStatus.offline,
+            pingMs: 0,
+            lastCheckedAt: DateTime.now(),
+            errorMessage: 'Search failed',
+          ),
+        );
+      }
+    }
+    return Success(posts);
+  }
+
+  Future<Result<Post?>> getPost(String providerId, String postId) async {
+    final providersResult = await activeProviders();
+    if (providersResult is Error<List<ContentProvider>>) {
+      return Error(providersResult.failure);
+    }
+    final providers = (providersResult as Success<List<ContentProvider>>).data;
+    final matches = providers.where((provider) => provider.id == providerId);
+    if (matches.isEmpty) {
+      return const Error(
+          Failure(code: 'not_found', message: 'Provider not found'));
+    }
+    try {
+      return Success(await matches.first.getPost(postId));
+    } catch (error) {
+      return Error(
+        Failure(
+          code: 'provider_get_post',
+          message: 'Could not load post',
+          details: error,
+        ),
+      );
+    }
+  }
+
+  Future<List<R>> _runLimited<T, R>(
+    List<T> items,
+    int concurrency,
+    Future<R> Function(T item) action,
+  ) async {
+    final results = <R>[];
+    var index = 0;
+
+    Future<void> worker() async {
+      while (index < items.length) {
+        final current = items[index++];
+        results.add(await action(current));
+      }
+    }
+
+    await Future.wait(
+      List.generate(concurrency.clamp(1, items.length), (_) => worker()),
+    );
+    return results;
+  }
+}

lib/backend/providers/rule34_provider.dart

@@ -0,0 +1,53 @@
+import '../mappers/rule34_mapper.dart';
+import '../models/post.dart';
+import '../models/top_period_filter.dart';
+import 'gelbooru_provider.dart';
+
+class Rule34Provider extends GelbooruProvider {
+  Rule34Provider({
+    required super.id,
+    required super.name,
+    required super.baseUrl,
+    required super.dioClient,
+    super.queryParameters,
+  });
+
+  @override
+  Future<List<Post>> searchPosts({
+    required List<String> tags,
+    required int page,
+    int limit = 50,
+    String? rating,
+    TopPeriodFilter topPeriod = TopPeriodFilter.none,
+  }) async {
+    final topTags = switch (topPeriod) {
+      TopPeriodFilter.none => const <String>[],
+      TopPeriodFilter.month ||
+      TopPeriodFilter.year ||
+      TopPeriodFilter.allTime =>
+        const ['sort:score:desc'],
+    };
+    final response = await dio.get<dynamic>(
+      '/index.php',
+      queryParameters: {
+        'page': 'dapi',
+        's': 'post',
+        'q': 'index',
+        'json': '1',
+        'pid': page,
+        'limit': limit,
+        'tags': [
+          ...tags,
+          if (rating != null) 'rating:$rating',
+          ...topTags,
+        ].join(' '),
+        ...queryParameters,
+      },
+    );
+    return Rule34Mapper.postsFromResponse(
+      response.data,
+      providerId: id,
+      providerName: name,
+    );
+  }
+}

lib/backend/repositories/collection_repository.dart

@@ -0,0 +1,105 @@
+import 'package:isar/isar.dart' hide Collection;
+
+import '../../core/database/app_database.dart';
+import '../../core/database/database_service.dart';
+import '../../core/utils/result.dart';
+import '../models/collection.dart';
+import '../models/post.dart';
+import 'post_repository.dart';
+
+class CollectionRepository {
+  CollectionRepository(this._databaseService, this._postRepository);
+
+  final DatabaseService _databaseService;
+  final PostRepository _postRepository;
+
+  Future<Result<Collection>> save(Collection collection) {
+    return _databaseService.safeWrite((isar) async {
+      await isar.collectionEntitys.put(
+        CollectionEntity()
+          ..collectionId = collection.id
+          ..name = collection.name
+          ..description = collection.description
+          ..coverUrl = collection.coverUrl
+          ..createdAt = collection.createdAt
+          ..updatedAt = collection.updatedAt,
+      );
+      return collection;
+    });
+  }
+
+  Future<Result<void>> delete(String id) {
+    return _databaseService.safeWrite((isar) async {
+      await isar.collectionPostEntitys
+          .filter()
+          .collectionIdEqualTo(id)
+          .deleteAll();
+      await isar.collectionEntitys.filter().collectionIdEqualTo(id).deleteAll();
+    });
+  }
+
+  Future<Result<List<Collection>>> all() {
+    return _databaseService.safeRead((isar) async {
+      final items = await isar.collectionEntitys.where().findAll();
+      items.sort((a, b) => b.updatedAt.compareTo(a.updatedAt));
+      return items.map((entity) => entity.toModel()).toList();
+    });
+  }
+
+  Future<Result<Collection?>> getById(String id) {
+    return _databaseService.safeRead((isar) async {
+      final entity = await isar.collectionEntitys
+          .filter()
+          .collectionIdEqualTo(id)
+          .findFirst();
+      return entity?.toModel();
+    });
+  }
+
+  Future<Result<void>> addPost(String collectionId, Post post) async {
+    await _postRepository.cachePosts([post]);
+    return _databaseService.safeWrite((isar) async {
+      await isar.collectionPostEntitys.put(
+        CollectionPostEntity()
+          ..linkKey = '$collectionId:${post.providerId}:${post.id}'
+          ..collectionId = collectionId
+          ..postId = post.id
+          ..providerId = post.providerId
+          ..addedAt = DateTime.now(),
+      );
+    });
+  }
+
+  Future<Result<void>> removePost(
+    String collectionId,
+    String postId,
+    String providerId,
+  ) {
+    return _databaseService.safeWrite((isar) async {
+      await isar.collectionPostEntitys
+          .filter()
+          .linkKeyEqualTo('$collectionId:$providerId:$postId')
+          .deleteAll();
+    });
+  }
+
+  Future<Result<List<Post>>> posts(String collectionId) {
+    return _databaseService.safeRead((isar) async {
+      final links = await isar.collectionPostEntitys
+          .filter()
+          .collectionIdEqualTo(collectionId)
+          .findAll();
+      links.sort((a, b) => b.addedAt.compareTo(a.addedAt));
+      final posts = <Post>[];
+      for (final link in links) {
+        final entity = await isar.cachedPostEntitys
+            .filter()
+            .providerIdEqualTo(link.providerId)
+            .postIdEqualTo(link.postId)
+            .findFirst();
+        if (entity != null) posts.add(entity.toModel());
+      }
+      return posts;
+    });
+  }
+}

lib/backend/repositories/favorite_repository.dart

@@ -0,0 +1,63 @@
+import 'package:isar/isar.dart';
+
+import '../../core/database/app_database.dart';
+import '../../core/database/database_service.dart';
+import '../../core/utils/result.dart';
+import '../models/favorite.dart';
+import '../models/post.dart';
+import 'post_repository.dart';
+
+class FavoriteRepository {
+  FavoriteRepository(this._databaseService, this._postRepository);
+
+  final DatabaseService _databaseService;
+  final PostRepository _postRepository;
+
+  Future<Result<void>> add(Post post) async {
+    await _postRepository.cachePosts([post]);
+    return _databaseService.safeWrite((isar) async {
+      final key = '${post.providerId}:${post.id}';
+      await isar.favoriteEntitys.put(
+        FavoriteEntity()
+          ..favoriteKey = key
+          ..favoriteId = key
+          ..postId = post.id
+          ..providerId = post.providerId
+          ..savedAt = DateTime.now(),
+      );
+    });
+  }
+
+  Future<Result<void>> remove(String postId, String providerId) {
+    return _databaseService.safeWrite((isar) async {
+      await isar.favoriteEntitys
+          .filter()
+          .favoriteKeyEqualTo('$providerId:$postId')
+          .deleteAll();
+    });
+  }
+
+  Future<Result<bool>> exists(String postId, String providerId) {
+    return _databaseService.safeRead((isar) async {
+      return await isar.favoriteEntitys
+              .filter()
+              .favoriteKeyEqualTo('$providerId:$postId')
+              .count() >
+          0;
+    });
+  }
+
+  Future<Result<List<Favorite>>> all() {
+    return _databaseService.safeRead((isar) async {
+      final items = await isar.favoriteEntitys.where().findAll();
+      items.sort((a, b) => b.savedAt.compareTo(a.savedAt));
+      return items.map((entity) => entity.toModel()).toList();
+    });
+  }
+
+  Future<Result<void>> clear() {
+    return _databaseService.safeWrite((isar) async {
+      await isar.favoriteEntitys.clear();
+    });
+  }
+}

lib/backend/repositories/post_repository.dart

@@ -0,0 +1,45 @@
+import 'package:isar/isar.dart';
+
+import '../../core/database/app_database.dart';
+import '../../core/database/database_service.dart';
+import '../../core/utils/result.dart';
+import '../models/post.dart';
+
+class PostRepository {
+  PostRepository(this._databaseService);
+
+  final DatabaseService _databaseService;
+
+  Future<Result<void>> cachePosts(List<Post> posts) {
+    return _databaseService.safeWrite((isar) async {
+      await isar.cachedPostEntitys.putAll(
+        posts.map((post) => CachedPostEntity.fromModel(post)).toList(),
+      );
+    });
+  }
+
+  Future<Result<Post?>> getCachedPost(String postId, String providerId) {
+    return _databaseService.safeRead((isar) async {
+      final entity = await isar.cachedPostEntitys
+          .filter()
+          .providerIdEqualTo(providerId)
+          .postIdEqualTo(postId)
+          .findFirst();
+      return entity?.toModel();
+    });
+  }
+
+  Future<Result<List<Post>>> getCachedPostsByKeys(Iterable<String> keys) {
+    return _databaseService.safeRead((isar) async {
+      final posts = <Post>[];
+      for (final key in keys) {
+        final entity = await isar.cachedPostEntitys
+            .filter()
+            .cacheKeyEqualTo(key)
+            .findFirst();
+        if (entity != null) posts.add(entity.toModel());
+      }
+      return posts;
+    });
+  }
+}

lib/backend/repositories/provider_repository.dart

@@ -0,0 +1,127 @@
+import 'package:isar/isar.dart';
+
+import '../../core/database/app_database.dart';
+import '../../core/database/database_service.dart';
+import '../../core/utils/result.dart';
+import '../models/content_provider_config.dart';
+import '../models/provider_health.dart';
+
+class ProviderRepository {
+  ProviderRepository(this._databaseService);
+
+  final DatabaseService _databaseService;
+
+  static List<ContentProviderConfig> seedProviders() {
+    final now = DateTime.now();
+    return [
+      ContentProviderConfig(
+        id: 'gelbooru',
+        name: 'Gelbooru',
+        baseUrl: 'https://gelbooru.com',
+        apiType: 'gelbooru',
+        enabled: true,
+        priority: 0,
+        timeoutSeconds: 20,
+        customHeaders: const {},
+        createdAt: now,
+        updatedAt: now,
+      ),
+      ContentProviderConfig(
+        id: 'rule34',
+        name: 'Rule34',
+        baseUrl: 'https://api.rule34.xxx',
+        apiType: 'rule34',
+        enabled: true,
+        priority: 1,
+        timeoutSeconds: 20,
+        customHeaders: const {},
+        createdAt: now,
+        updatedAt: now,
+      ),
+      ContentProviderConfig(
+        id: 'safebooru',
+        name: 'Safebooru',
+        baseUrl: 'https://safebooru.org',
+        apiType: 'gelbooru',
+        enabled: true,
+        priority: 2,
+        timeoutSeconds: 20,
+        customHeaders: const {},
+        createdAt: now,
+        updatedAt: now,
+      ),
+    ];
+  }
+
+  Future<Result<void>> ensureSeedProviders() {
+    return _databaseService.safeWrite((isar) async {
+      final count = await isar.providerConfigEntitys.count();
+      if (count > 0) return;
+      await isar.providerConfigEntitys.putAll(
+        seedProviders().map(ProviderConfigEntity.fromModel).toList(),
+      );
+    });
+  }
+
+  Future<Result<List<ContentProviderConfig>>> getProviders({
+    bool enabledOnly = false,
+  }) {
+    return _databaseService.safeRead((isar) async {
+      final providers = enabledOnly
+          ? await isar.providerConfigEntitys
+              .filter()
+              .enabledEqualTo(true)
+              .findAll()
+          : await isar.providerConfigEntitys.where().findAll();
+      providers.sort((a, b) => a.priority.compareTo(b.priority));
+      return providers.map((entity) => entity.toModel()).toList();
+    });
+  }
+
+  Future<Result<ContentProviderConfig?>> getProvider(String id) {
+    return _databaseService.safeRead((isar) async {
+      final entity = await isar.providerConfigEntitys
+          .filter()
+          .providerIdEqualTo(id)
+          .findFirst();
+      return entity?.toModel();
+    });
+  }
+
+  Future<Result<void>> saveProvider(ContentProviderConfig config) {
+    return _databaseService.safeWrite((isar) async {
+      await isar.providerConfigEntitys
+          .put(ProviderConfigEntity.fromModel(config));
+    });
+  }
+
+  Future<Result<void>> deleteProvider(String id) {
+    return _databaseService.safeWrite((isar) async {
+      await isar.providerConfigEntitys
+          .filter()
+          .providerIdEqualTo(id)
+          .deleteAll();
+      await isar.providerHealthEntitys
+          .filter()
+          .providerIdEqualTo(id)
+          .deleteAll();
+    });
+  }
+
+  Future<Result<void>> saveHealth(ProviderHealth health) {
+    return _databaseService.safeWrite((isar) async {
+      await isar.providerHealthEntitys
+          .put(ProviderHealthEntity.fromModel(health));
+    });
+  }
+
+  Future<Result<ProviderHealth?>> getHealth(String providerId) {
+    return _databaseService.safeRead((isar) async {
+      final entity = await isar.providerHealthEntitys
+          .filter()
+          .providerIdEqualTo(providerId)
+          .findFirst();
+      return entity?.toModel();
+    });
+  }
+}

lib/backend/repositories/search_repository.dart

@@ -0,0 +1,39 @@
+import 'package:isar/isar.dart';
+
+import '../../core/database/app_database.dart';
+import '../../core/database/database_service.dart';
+import '../../core/utils/result.dart';
+import '../models/search_history.dart';
+
+class SearchRepository {
+  SearchRepository(this._databaseService);
+
+  final DatabaseService _databaseService;
+
+  Future<Result<void>> save(SearchHistory history) {
+    return _databaseService.safeWrite((isar) async {
+      await isar.searchHistoryEntitys.put(
+        SearchHistoryEntity()
+          ..historyId = history.id
+          ..query = history.query
+          ..tags = history.tags
+          ..searchedAt = history.searchedAt
+          ..resultCount = history.resultCount,
+      );
+    });
+  }
+
+  Future<Result<List<SearchHistory>>> recent({int limit = 20}) {
+    return _databaseService.safeRead((isar) async {
+      final items = await isar.searchHistoryEntitys.where().findAll();
+      items.sort((a, b) => b.searchedAt.compareTo(a.searchedAt));
+      return items.take(limit).map((entity) => entity.toModel()).toList();
+    });
+  }
+
+  Future<Result<void>> clear() {
+    return _databaseService.safeWrite((isar) async {
+      await isar.searchHistoryEntitys.clear();
+    });
+  }
+}

lib/backend/services/collection_service.dart

@@ -0,0 +1,71 @@
+import '../../core/utils/result.dart';
+import '../../core/errors/failure.dart';
+import '../models/collection.dart';
+import '../models/post.dart';
+import '../repositories/collection_repository.dart';
+
+class CollectionService {
+  CollectionService(this._repository);
+
+  final CollectionRepository _repository;
+
+  Future<Result<Collection>> createCollection(
+      String name, String? description) {
+    final now = DateTime.now();
+    return _repository.save(
+      Collection(
+        id: now.microsecondsSinceEpoch.toString(),
+        name: name,
+        description: description,
+        createdAt: now,
+        updatedAt: now,
+      ),
+    );
+  }
+
+  Future<Result<Collection>> updateCollection(
+    String id, {
+    required String name,
+    String? description,
+    String? coverUrl,
+  }) async {
+    final existingResult = await _repository.getById(id);
+    if (existingResult is Error<Collection?>) {
+      return Error(existingResult.failure);
+    }
+    final existing = (existingResult as Success<Collection?>).data;
+    if (existing == null) {
+      return const Error(
+        Failure(code: 'not_found', message: 'Collection not found'),
+      );
+    }
+    return _repository.save(
+      Collection(
+        id: id,
+        name: name,
+        description: description,
+        coverUrl: coverUrl,
+        createdAt: existing.createdAt,
+        updatedAt: DateTime.now(),
+      ),
+    );
+  }
+
+  Future<Result<void>> deleteCollection(String id) => _repository.delete(id);
+  Future<Result<void>> addPostToCollection(String collectionId, Post post) {
+    return _repository.addPost(collectionId, post);
+  }
+
+  Future<Result<void>> removePostFromCollection(
+    String collectionId,
+    String postId,
+    String providerId,
+  ) {
+    return _repository.removePost(collectionId, postId, providerId);
+  }
+
+  Future<Result<List<Collection>>> getCollections() => _repository.all();
+  Future<Result<List<Post>>> getCollectionPosts(String collectionId) {
+    return _repository.posts(collectionId);
+  }
+}

lib/backend/services/favorite_service.dart

@@ -0,0 +1,37 @@
+import '../../core/utils/result.dart';
+import '../models/favorite.dart';
+import '../models/post.dart';
+import '../repositories/favorite_repository.dart';
+import '../repositories/post_repository.dart';
+
+class FavoriteService {
+  FavoriteService(this._repository, [this._postRepository]);
+
+  final FavoriteRepository _repository;
+  final PostRepository? _postRepository;
+
+  Future<Result<void>> addFavorite(Post post) => _repository.add(post);
+  Future<Result<void>> removeFavorite(String postId, String providerId) {
+    return _repository.remove(postId, providerId);
+  }
+
+  Future<Result<bool>> isFavorite(String postId, String providerId) {
+    return _repository.exists(postId, providerId);
+  }
+
+  Future<Result<List<Favorite>>> getFavorites() => _repository.all();
+  Future<Result<List<Post>>> getFavoritePosts() async {
+    final postRepository = _postRepository;
+    if (postRepository == null) return const Success([]);
+    final favoritesResult = await _repository.all();
+    if (favoritesResult is Error<List<Favorite>>) {
+      return Error(favoritesResult.failure);
+    }
+    final favorites = (favoritesResult as Success<List<Favorite>>).data;
+    return postRepository.getCachedPostsByKeys(
+      favorites.map((favorite) => '${favorite.providerId}:${favorite.postId}'),
+    );
+  }
+
+  Future<Result<void>> clearFavorites() => _repository.clear();
+}

lib/backend/services/feed_service.dart

@@ -0,0 +1,70 @@
+import '../../core/cache/cache_service.dart';
+import '../../core/utils/result.dart';
+import '../models/post.dart';
+import '../models/top_period_filter.dart';
+import '../providers/provider_manager.dart';
+import 'settings_service.dart';
+
+class FeedService {
+  FeedService(this._providerManager, this._cacheService, this._settingsService);
+
+  final ProviderManager _providerManager;
+  final CacheService _cacheService;
+  final SettingsService _settingsService;
+  final Map<String, int> _pages = {};
+
+  String _key(
+    List<String> tags,
+    String? rating,
+    String? providerId,
+    TopPeriodFilter topPeriod,
+  ) {
+    final sorted = [...tags]..sort();
+    return '${sorted.join(' ')}|${rating ?? ''}|${providerId ?? ''}|${topPeriod.name}';
+  }
+
+  Future<Result<List<Post>>> refresh({
+    List<String> tags = const [],
+    String? rating,
+    String? providerId,
+    TopPeriodFilter topPeriod = TopPeriodFilter.none,
+    int limit = 50,
+  }) {
+    _pages[_key(tags, rating, providerId, topPeriod)] = 0;
+    return loadNextPage(
+      tags: tags,
+      rating: rating,
+      providerId: providerId,
+      topPeriod: topPeriod,
+      limit: limit,
+    );
+  }
+
+  Future<Result<List<Post>>> loadNextPage({
+    List<String> tags = const [],
+    String? rating,
+    String? providerId,
+    TopPeriodFilter topPeriod = TopPeriodFilter.none,
+    int limit = 50,
+  }) async {
+    final key = _key(tags, rating, providerId, topPeriod);
+    final page = _pages[key] ?? 0;
+    final result = await _providerManager.searchAcrossProviders(
+      tags: tags,
+      page: page,
+      limit: limit,
+      rating: rating,
+      providerId: providerId,
+      topPeriod: topPeriod,
+    );
+    if (result is Error<List<Post>>) return Error(result.failure);
+    final posts = (result as Success<List<Post>>).data;
+    _pages[key] = page + 1;
+    final settingsResult = await _settingsService.getSettings();
+    final maxItems = settingsResult is Success<AppSettings>
+        ? settingsResult.data.cacheMaxItems
+        : null;
+    await _cacheService.cachePosts(posts, maxItems: maxItems);
+    return Success(posts);
+  }
+}

lib/backend/services/provider_check_service.dart

@@ -0,0 +1,35 @@
+import '../../core/errors/failure.dart';
+import '../../core/utils/result.dart';
+import '../models/content_provider_config.dart';
+import '../models/provider_health.dart';
+import '../providers/provider_factory.dart';
+import '../providers/provider_manager.dart';
+import '../repositories/provider_repository.dart';
+
+class ProviderCheckService {
+  ProviderCheckService(this._repository, this._factory, this._manager);
+
+  final ProviderRepository _repository;
+  final ProviderFactory _factory;
+  final ProviderManager _manager;
+
+  Future<Result<ProviderHealth>> checkOne(String providerId) async {
+    final configResult = await _repository.getProvider(providerId);
+    if (configResult is Error<ContentProviderConfig?>) {
+      return Error(configResult.failure);
+    }
+    final config = (configResult as Success<ContentProviderConfig?>).data;
+    if (config == null) {
+      return const Error(
+        Failure(code: 'not_found', message: 'Provider not found'),
+      );
+    }
+    final health = await _factory.create(config).checkHealth();
+    await _repository.saveHealth(health);
+    return Success(health);
+  }
+
+  Future<Result<List<ProviderHealth>>> checkAll() {
+    return _manager.checkAll(concurrency: 3);
+  }
+}

lib/backend/services/search_service.dart

@@ -0,0 +1,55 @@
+import '../../core/utils/result.dart';
+import '../models/search_history.dart';
+import '../repositories/search_repository.dart';
+
+class SearchService {
+  SearchService(this._repository);
+
+  final SearchRepository _repository;
+
+  List<String> parseTags(String query) {
+    return query
+        .trim()
+        .split(RegExp(r'\s+'))
+        .where((tag) => tag.isNotEmpty)
+        .toSet()
+        .toList();
+  }
+
+  Future<Result<void>> saveSearch(String query, int resultCount) {
+    final tags = parseTags(query);
+    return _repository.save(
+      SearchHistory(
+        id: '${DateTime.now().microsecondsSinceEpoch}:${tags.join(',')}',
+        query: query.trim(),
+        tags: tags,
+        searchedAt: DateTime.now(),
+        resultCount: resultCount,
+      ),
+    );
+  }
+
+  Future<Result<List<SearchHistory>>> recentSearches({int limit = 20}) {
+    return _repository.recent(limit: limit);
+  }
+
+  Future<Result<List<String>>> autocomplete(String prefix,
+      {int limit = 10}) async {
+    final recent = await _repository.recent(limit: 100);
+    return recent.fold(
+      onSuccess: (items) {
+        final needle = prefix.toLowerCase();
+        final values = <String>{};
+        for (final item in items) {
+          for (final tag in item.tags) {
+            if (tag.toLowerCase().startsWith(needle)) values.add(tag);
+          }
+        }
+        return Success(values.take(limit).toList());
+      },
+      onError: Error<List<String>>.new,
+    );
+  }
+
+  Future<Result<void>> clearHistory() => _repository.clear();
+}

lib/backend/services/settings_service.dart

@@ -0,0 +1,254 @@
+import 'dart:convert';
+
+import 'package:isar/isar.dart';
+
+import '../../core/database/app_database.dart';
+import '../../core/database/database_service.dart';
+import '../../core/errors/failure.dart';
+import '../../core/utils/result.dart';
+import '../models/content_provider_config.dart';
+import '../repositories/provider_repository.dart';
+
+class AppSettings {
+  const AppSettings({
+    required this.enabledProviderIds,
+    required this.nsfwEnabled,
+    required this.cacheTtlHours,
+    required this.cacheMaxItems,
+    required this.providerPriority,
+    required this.themeMode,
+    required this.desktopColumns,
+    required this.mobileColumns,
+    required this.blurExplicitContent,
+    required this.allowDownloads,
+    required this.selectedFeedProviderIds,
+    required this.showPostBadges,
+    required this.defaultTopPeriodFilter,
+    this.defaultRatingFilter,
+  });
+
+  final List<String> enabledProviderIds;
+  final bool nsfwEnabled;
+  final int cacheTtlHours;
+  final int cacheMaxItems;
+  final Map<String, int> providerPriority;
+  final String themeMode;
+  final int desktopColumns;
+  final int mobileColumns;
+  final bool blurExplicitContent;
+  final bool allowDownloads;
+  final List<String> selectedFeedProviderIds;
+  final bool showPostBadges;
+  final String defaultTopPeriodFilter;
+  final String? defaultRatingFilter;
+
+  static const defaults = AppSettings(
+    enabledProviderIds: ['gelbooru', 'rule34', 'safebooru'],
+    nsfwEnabled: true,
+    cacheTtlHours: 24,
+    cacheMaxItems: 2000,
+    providerPriority: {'gelbooru': 0, 'rule34': 1, 'safebooru': 2},
+    themeMode: 'dark',
+    desktopColumns: 5,
+    mobileColumns: 2,
+    blurExplicitContent: true,
+    allowDownloads: true,
+    selectedFeedProviderIds: [],
+    showPostBadges: true,
+    defaultTopPeriodFilter: 'none',
+    defaultRatingFilter: null,
+  );
+
+  AppSettings copyWith({
+    List<String>? enabledProviderIds,
+    bool? nsfwEnabled,
+    int? cacheTtlHours,
+    int? cacheMaxItems,
+    Map<String, int>? providerPriority,
+    String? themeMode,
+    int? desktopColumns,
+    int? mobileColumns,
+    bool? blurExplicitContent,
+    bool? allowDownloads,
+    List<String>? selectedFeedProviderIds,
+    bool? showPostBadges,
+    String? defaultTopPeriodFilter,
+    String? defaultRatingFilter,
+  }) {
+    return AppSettings(
+      enabledProviderIds: enabledProviderIds ?? this.enabledProviderIds,
+      nsfwEnabled: nsfwEnabled ?? this.nsfwEnabled,
+      cacheTtlHours: cacheTtlHours ?? this.cacheTtlHours,
+      cacheMaxItems: cacheMaxItems ?? this.cacheMaxItems,
+      providerPriority: providerPriority ?? this.providerPriority,
+      themeMode: themeMode ?? this.themeMode,
+      desktopColumns: desktopColumns ?? this.desktopColumns,
+      mobileColumns: mobileColumns ?? this.mobileColumns,
+      blurExplicitContent: blurExplicitContent ?? this.blurExplicitContent,
+      allowDownloads: allowDownloads ?? this.allowDownloads,
+      selectedFeedProviderIds:
+          selectedFeedProviderIds ?? this.selectedFeedProviderIds,
+      showPostBadges: showPostBadges ?? this.showPostBadges,
+      defaultTopPeriodFilter:
+          defaultTopPeriodFilter ?? this.defaultTopPeriodFilter,
+      defaultRatingFilter: defaultRatingFilter ?? this.defaultRatingFilter,
+    );
+  }
+
+  Map<String, dynamic> toJson() => {
+        'enabledProviderIds': enabledProviderIds,
+        'nsfwEnabled': nsfwEnabled,
+        'cacheTtlHours': cacheTtlHours,
+        'cacheMaxItems': cacheMaxItems,
+        'providerPriority': providerPriority,
+        'themeMode': themeMode,
+        'desktopColumns': desktopColumns,
+        'mobileColumns': mobileColumns,
+        'blurExplicitContent': blurExplicitContent,
+        'allowDownloads': allowDownloads,
+        'selectedFeedProviderIds': selectedFeedProviderIds,
+        'showPostBadges': showPostBadges,
+        'defaultTopPeriodFilter': defaultTopPeriodFilter,
+        'defaultRatingFilter': defaultRatingFilter,
+      };
+
+  factory AppSettings.fromJson(Map<String, dynamic> json) => AppSettings(
+        enabledProviderIds: List<String>.from(
+          (json['enabledProviderIds'] as List?) ?? defaults.enabledProviderIds,
+        ),
+        nsfwEnabled: (json['nsfwEnabled'] as bool?) ?? defaults.nsfwEnabled,
+        cacheTtlHours:
+            (json['cacheTtlHours'] as num?)?.toInt() ?? defaults.cacheTtlHours,
+        cacheMaxItems:
+            (json['cacheMaxItems'] as num?)?.toInt() ?? defaults.cacheMaxItems,
+        providerPriority: Map<String, int>.from(
+          (json['providerPriority'] as Map?) ?? defaults.providerPriority,
+        ),
+        themeMode: (json['themeMode'] as String?) ?? defaults.themeMode,
+        desktopColumns: (json['desktopColumns'] as num?)?.toInt() ??
+            defaults.desktopColumns,
+        mobileColumns:
+            (json['mobileColumns'] as num?)?.toInt() ?? defaults.mobileColumns,
+        blurExplicitContent: (json['blurExplicitContent'] as bool?) ??
+            defaults.blurExplicitContent,
+        allowDownloads:
+            (json['allowDownloads'] as bool?) ?? defaults.allowDownloads,
+        selectedFeedProviderIds: List<String>.from(
+          (json['selectedFeedProviderIds'] as List?) ??
+              defaults.selectedFeedProviderIds,
+        ),
+        showPostBadges:
+            (json['showPostBadges'] as bool?) ?? defaults.showPostBadges,
+        defaultTopPeriodFilter: (json['defaultTopPeriodFilter'] as String?) ??
+            defaults.defaultTopPeriodFilter,
+        defaultRatingFilter: json['defaultRatingFilter'] as String?,
+      );
+}
+
+class SettingsService {
+  SettingsService(
+    this._databaseService, {
+    ProviderRepository? providerRepository,
+  }) : _providerRepository = providerRepository;
+
+  final DatabaseService _databaseService;
+  final ProviderRepository? _providerRepository;
+  static const _settingsKey = 'app_settings';
+
+  Future<Result<AppSettings>> getSettings() {
+    return _databaseService.safeRead((isar) async {
+      final entity = await isar.appSettingEntitys
+          .filter()
+          .keyEqualTo(_settingsKey)
+          .findFirst();
+      if (entity == null) return AppSettings.defaults;
+      return AppSettings.fromJson(
+          jsonDecode(entity.jsonValue) as Map<String, dynamic>);
+    });
+  }
+
+  Future<Result<void>> updateSettings(AppSettings settings) {
+    return _databaseService.safeWrite((isar) async {
+      await isar.appSettingEntitys.put(
+        AppSettingEntity()
+          ..key = _settingsKey
+          ..jsonValue = jsonEncode(settings.toJson())
+          ..updatedAt = DateTime.now(),
+      );
+    });
+  }
+
+  Future<Result<void>> saveEnabledProviders(List<String> providerIds) async {
+    final result = await getSettings();
+    if (result is Error<AppSettings>) return Error(result.failure);
+    final settings = (result as Success<AppSettings>).data;
+    final updateResult = await updateSettings(
+        settings.copyWith(enabledProviderIds: providerIds));
+    if (updateResult is Error<void>) return updateResult;
+
+    final repository = _providerRepository;
+    if (repository == null) return updateResult;
+
+    final providersResult = await repository.getProviders();
+    if (providersResult is Error<List<ContentProviderConfig>>) {
+      return Error(providersResult.failure);
+    }
+    final enabled = providerIds.toSet();
+    for (final provider
+        in (providersResult as Success<List<ContentProviderConfig>>).data) {
+      await repository.saveProvider(
+        provider.copyWith(
+          enabled: enabled.contains(provider.id),
+          updatedAt: DateTime.now(),
+        ),
+      );
+    }
+    return updateResult;
+  }
+
+  Future<Result<void>> saveNsfwFilter(bool enabled) async {
+    final result = await getSettings();
+    if (result is Error<AppSettings>) return Error(result.failure);
+    final settings = (result as Success<AppSettings>).data;
+    return updateSettings(settings.copyWith(nsfwEnabled: enabled));
+  }
+
+  Future<Result<void>> saveCacheSettings({
+    required int ttlHours,
+    required int maxItems,
+  }) async {
+    final result = await getSettings();
+    if (result is Error<AppSettings>) return Error(result.failure);
+    final settings = (result as Success<AppSettings>).data;
+    return updateSettings(
+      settings.copyWith(cacheTtlHours: ttlHours, cacheMaxItems: maxItems),
+    );
+  }
+
+  Future<Result<String>> exportSettingsToJson() async {
+    final result = await getSettings();
+    return result.fold(
+      onSuccess: (settings) => Success(jsonEncode(settings.toJson())),
+      onError: Error<String>.new,
+    );
+  }
+
+  Future<Result<void>> importSettingsFromJson(String json) async {
+    try {
+      final settings =
+          AppSettings.fromJson(jsonDecode(json) as Map<String, dynamic>);
+      final result = await updateSettings(settings);
+      if (result is Error<void>) return result;
+      await saveEnabledProviders(settings.enabledProviderIds);
+      return result;
+    } catch (error) {
+      return Error(
+        Failure(
+          code: 'settings_import',
+          message: 'Invalid settings JSON',
+          details: error,
+        ),
+      );
+    }
+  }
+}

lib/core/cache/cache_service.dart

@@ -0,0 +1,73 @@
+import 'package:isar/isar.dart';
+
+import '../database/app_database.dart';
+import '../database/database_service.dart';
+import '../utils/result.dart';
+import '../../backend/models/post.dart';
+
+class CacheService {
+  CacheService(this._databaseService);
+
+  final DatabaseService _databaseService;
+
+  Future<Result<void>> cachePosts(
+    List<Post> posts, {
+    int? maxItems,
+  }) {
+    return _databaseService.safeWrite((isar) async {
+      await isar.cachedPostEntitys.putAll(
+        posts.map((post) => CachedPostEntity.fromModel(post)).toList(),
+      );
+      if (maxItems != null && maxItems > 0) {
+        await _evictOverflow(isar, maxItems);
+      }
+    });
+  }
+
+  Future<Result<List<Post>>> getCachedPosts({
+    Duration maxAge = const Duration(hours: 24),
+  }) {
+    return _databaseService.safeRead((isar) async {
+      final cutoff = DateTime.now().subtract(maxAge);
+      final entities = await isar.cachedPostEntitys
+          .filter()
+          .cachedAtGreaterThan(cutoff)
+          .findAll();
+      entities.sort((a, b) => b.cachedAt.compareTo(a.cachedAt));
+      return entities.map((entity) => entity.toModel()).toList();
+    });
+  }
+
+  Future<Result<void>> prune({
+    Duration? olderThan,
+    int? maxItems,
+  }) {
+    return _databaseService.safeWrite((isar) async {
+      if (olderThan != null) {
+        final cutoff = DateTime.now().subtract(olderThan);
+        await isar.cachedPostEntitys
+            .filter()
+            .cachedAtLessThan(cutoff)
+            .deleteAll();
+      }
+      if (maxItems != null && maxItems > 0) {
+        await _evictOverflow(isar, maxItems);
+      }
+    });
+  }
+
+  Future<Result<void>> clear() {
+    return _databaseService.safeWrite((isar) async {
+      await isar.cachedPostEntitys.clear();
+    });
+  }
+
+  Future<void> _evictOverflow(Isar isar, int maxItems) async {
+    final entities = await isar.cachedPostEntitys.where().findAll();
+    if (entities.length <= maxItems) return;
+    entities.sort((a, b) => b.cachedAt.compareTo(a.cachedAt));
+    final overflowIds =
+        entities.skip(maxItems).map((entity) => entity.isarId).toList();
+    await isar.cachedPostEntitys.deleteAll(overflowIds);
+  }
+}

lib/core/cache/image_cache_service.dart

@@ -0,0 +1,7 @@
+import '../../backend/models/post.dart';
+
+class ImageCacheService {
+  String previewCacheKey(Post post) => 'preview:${post.providerId}:${post.id}';
+  String sampleCacheKey(Post post) => 'sample:${post.providerId}:${post.id}';
+  String fileCacheKey(Post post) => 'file:${post.providerId}:${post.id}';
+}

lib/core/database/app_database.dart

@@ -0,0 +1,264 @@
+import 'dart:convert';
+
+import 'package:isar/isar.dart' hide Collection;
+import 'package:path_provider/path_provider.dart';
+
+import '../../backend/models/collection.dart';
+import '../../backend/models/content_provider_config.dart';
+import '../../backend/models/favorite.dart';
+import '../../backend/models/post.dart';
+import '../../backend/models/provider_health.dart';
+import '../../backend/models/search_history.dart';
+
+part 'app_database.g.dart';
+
+class AppDatabase {
+  AppDatabase(this.isar);
+
+  final Isar isar;
+
+  static Future<AppDatabase> open({String? directory}) async {
+    final dir = directory ?? (await getApplicationDocumentsDirectory()).path;
+    final isar = await Isar.open(
+      [
+        ProviderConfigEntitySchema,
+        ProviderHealthEntitySchema,
+        CachedPostEntitySchema,
+        FavoriteEntitySchema,
+        CollectionEntitySchema,
+        CollectionPostEntitySchema,
+        SearchHistoryEntitySchema,
+        AppSettingEntitySchema,
+      ],
+      directory: dir,
+      name: 'gel_rule_app',
+    );
+    return AppDatabase(isar);
+  }
+
+  Future<void> close() => isar.close();
+}
+
+@collection
+class ProviderConfigEntity {
+  Id isarId = Isar.autoIncrement;
+
+  @Index(unique: true, replace: true)
+  late String providerId;
+  late String name;
+  late String baseUrl;
+  late String apiType;
+  late bool enabled;
+  late int priority;
+  late int timeoutSeconds;
+  late String customHeadersJson;
+  late DateTime createdAt;
+  late DateTime updatedAt;
+
+  ContentProviderConfig toModel() => ContentProviderConfig(
+        id: providerId,
+        name: name,
+        baseUrl: baseUrl,
+        apiType: apiType,
+        enabled: enabled,
+        priority: priority,
+        timeoutSeconds: timeoutSeconds,
+        customHeaders: Map<String, String>.from(
+          jsonDecode(customHeadersJson) as Map,
+        ),
+        createdAt: createdAt,
+        updatedAt: updatedAt,
+      );
+
+  static ProviderConfigEntity fromModel(ContentProviderConfig model) {
+    return ProviderConfigEntity()
+      ..providerId = model.id
+      ..name = model.name
+      ..baseUrl = model.baseUrl
+      ..apiType = model.apiType
+      ..enabled = model.enabled
+      ..priority = model.priority
+      ..timeoutSeconds = model.timeoutSeconds
+      ..customHeadersJson = jsonEncode(model.customHeaders)
+      ..createdAt = model.createdAt
+      ..updatedAt = model.updatedAt;
+  }
+}
+
+@collection
+class ProviderHealthEntity {
+  Id isarId = Isar.autoIncrement;
+
+  @Index(unique: true, replace: true)
+  late String providerId;
+  @enumerated
+  late ProviderStatus status;
+  late int pingMs;
+  late DateTime lastCheckedAt;
+  String? errorMessage;
+  String? apiVersion;
+
+  ProviderHealth toModel() => ProviderHealth(
+        providerId: providerId,
+        status: status,
+        pingMs: pingMs,
+        lastCheckedAt: lastCheckedAt,
+        errorMessage: errorMessage,
+        apiVersion: apiVersion,
+      );
+
+  static ProviderHealthEntity fromModel(ProviderHealth model) {
+    return ProviderHealthEntity()
+      ..providerId = model.providerId
+      ..status = model.status
+      ..pingMs = model.pingMs
+      ..lastCheckedAt = model.lastCheckedAt
+      ..errorMessage = model.errorMessage
+      ..apiVersion = model.apiVersion;
+  }
+}
+
+@collection
+class CachedPostEntity {
+  Id isarId = Isar.autoIncrement;
+
+  @Index(unique: true, replace: true)
+  late String cacheKey;
+  @Index(composite: [CompositeIndex('postId')])
+  late String providerId;
+  late String postId;
+  late String providerName;
+  late String previewUrl;
+  late String sampleUrl;
+  late String fileUrl;
+  late List<String> tags;
+  late String rating;
+  late int width;
+  late int height;
+  String? source;
+  late DateTime createdAt;
+  late String fileType;
+  late int score;
+  late DateTime cachedAt;
+
+  Post toModel() => Post(
+        id: postId,
+        providerId: providerId,
+        providerName: providerName,
+        previewUrl: previewUrl,
+        sampleUrl: sampleUrl,
+        fileUrl: fileUrl,
+        tags: tags,
+        rating: rating,
+        width: width,
+        height: height,
+        source: source,
+        createdAt: createdAt,
+        fileType: fileType,
+        score: score,
+      );
+
+  static CachedPostEntity fromModel(Post model, {DateTime? cachedAt}) {
+    return CachedPostEntity()
+      ..cacheKey = model.cacheKey
+      ..providerId = model.providerId
+      ..postId = model.id
+      ..providerName = model.providerName
+      ..previewUrl = model.previewUrl
+      ..sampleUrl = model.sampleUrl
+      ..fileUrl = model.fileUrl
+      ..tags = model.tags
+      ..rating = model.rating
+      ..width = model.width
+      ..height = model.height
+      ..source = model.source
+      ..createdAt = model.createdAt
+      ..fileType = model.fileType
+      ..score = model.score
+      ..cachedAt = cachedAt ?? DateTime.now();
+  }
+}
+
+@collection
+class FavoriteEntity {
+  Id isarId = Isar.autoIncrement;
+
+  @Index(unique: true, replace: true)
+  late String favoriteKey;
+  late String favoriteId;
+  late String postId;
+  late String providerId;
+  late DateTime savedAt;
+
+  Favorite toModel() => Favorite(
+        id: favoriteId,
+        postId: postId,
+        providerId: providerId,
+        savedAt: savedAt,
+      );
+}
+
+@collection
+class CollectionEntity {
+  Id isarId = Isar.autoIncrement;
+
+  @Index(unique: true, replace: true)
+  late String collectionId;
+  late String name;
+  String? description;
+  String? coverUrl;
+  late DateTime createdAt;
+  late DateTime updatedAt;
+
+  Collection toModel() => Collection(
+        id: collectionId,
+        name: name,
+        description: description,
+        coverUrl: coverUrl,
+        createdAt: createdAt,
+        updatedAt: updatedAt,
+      );
+}
+
+@collection
+class CollectionPostEntity {
+  Id isarId = Isar.autoIncrement;
+
+  @Index(unique: true, replace: true)
+  late String linkKey;
+  @Index()
+  late String collectionId;
+  late String postId;
+  late String providerId;
+  late DateTime addedAt;
+}
+
+@collection
+class SearchHistoryEntity {
+  Id isarId = Isar.autoIncrement;
+
+  @Index(unique: true, replace: true)
+  late String historyId;
+  late String query;
+  late List<String> tags;
+  late DateTime searchedAt;
+  late int resultCount;
+
+  SearchHistory toModel() => SearchHistory(
+        id: historyId,
+        query: query,
+        tags: tags,
+        searchedAt: searchedAt,
+        resultCount: resultCount,
+      );
+}
+
+@collection
+class AppSettingEntity {
+  Id isarId = Isar.autoIncrement;
+
+  @Index(unique: true, replace: true)
+  late String key;
+  late String jsonValue;
+  late DateTime updatedAt;
+}

lib/core/database/database_service.dart

@@ -0,0 +1,32 @@
+import 'package:isar/isar.dart';
+
+import '../errors/app_exception.dart';
+import '../utils/result.dart';
+import 'app_database.dart';
+
+class DatabaseService {
+  DatabaseService(this.database);
+
+  final AppDatabase database;
+
+  Isar get isar => database.isar;
+
+  Future<Result<T>> safeRead<T>(Future<T> Function(Isar isar) action) async {
+    try {
+      return Success(await action(isar));
+    } catch (error) {
+      return Error(
+          DatabaseException(error.toString(), details: error).toFailure());
+    }
+  }
+
+  Future<Result<T>> safeWrite<T>(Future<T> Function(Isar isar) action) async {
+    try {
+      final value = await isar.writeTxn(() => action(isar));
+      return Success(value);
+    } catch (error) {
+      return Error(
+          DatabaseException(error.toString(), details: error).toFailure());
+    }
+  }
+}

lib/core/errors/app_exception.dart

@@ -0,0 +1,54 @@
+import 'failure.dart';
+
+sealed class AppException implements Exception {
+  const AppException(this.message, {this.details});
+
+  final String message;
+  final Object? details;
+
+  String get code;
+
+  Failure toFailure() =>
+      Failure(code: code, message: message, details: details);
+}
+
+class NetworkException extends AppException {
+  const NetworkException(super.message, {super.details});
+  @override
+  String get code => 'network';
+}
+
+class RequestTimeoutException extends AppException {
+  const RequestTimeoutException(super.message, {super.details});
+  @override
+  String get code => 'timeout';
+}
+
+class ProviderUnavailableException extends AppException {
+  const ProviderUnavailableException(super.message, {super.details});
+  @override
+  String get code => 'provider_unavailable';
+}
+
+class BadResponseException extends AppException {
+  const BadResponseException(super.message, {super.details});
+  @override
+  String get code => 'bad_response';
+}
+
+class DatabaseException extends AppException {
+  const DatabaseException(super.message, {super.details});
+  @override
+  String get code => 'database';
+}
+
+class UnknownException extends AppException {
+  const UnknownException(super.message, {super.details});
+  @override
+  String get code => 'unknown';
+}
+
+Failure failureFromObject(Object error) {
+  if (error is AppException) return error.toFailure();
+  return UnknownException(error.toString(), details: error).toFailure();
+}

lib/core/errors/failure.dart

@@ -0,0 +1,14 @@
+class Failure {
+  const Failure({
+    required this.code,
+    required this.message,
+    this.details,
+  });
+
+  final String code;
+  final String message;
+  final Object? details;
+
+  @override
+  String toString() => 'Failure($code, $message)';
+}

lib/core/http/dio_client.dart

@@ -0,0 +1,117 @@
+import 'dart:async';
+import 'dart:math';
+
+import 'package:dio/dio.dart';
+import 'package:flutter/foundation.dart';
+
+import '../errors/app_exception.dart';
+import '../utils/result.dart';
+
+class DioClient {
+  DioClient({
+    String? baseUrl,
+    Duration timeout = const Duration(seconds: 20),
+    Map<String, String>? headers,
+    Dio? dio,
+  }) : dio = dio ?? Dio(_options(baseUrl, timeout, headers)) {
+    this.dio.interceptors.add(_RetryInterceptor(this.dio));
+    if (kDebugMode) {
+      this.dio.interceptors.add(
+            LogInterceptor(
+              requestBody: false,
+              responseBody: false,
+              requestHeader: false,
+              responseHeader: false,
+            ),
+          );
+    }
+  }
+
+  final Dio dio;
+
+  static BaseOptions _options(
+    String? baseUrl,
+    Duration timeout,
+    Map<String, String>? headers,
+  ) {
+    return BaseOptions(
+      baseUrl: baseUrl ?? '',
+      connectTimeout: timeout,
+      receiveTimeout: timeout,
+      sendTimeout: timeout,
+      headers: {
+        'User-Agent': 'GelRuleApp/0.1 Flutter local booru browser',
+        'Accept': 'application/json, text/xml;q=0.9, */*;q=0.8',
+        ...?headers,
+      },
+    );
+  }
+
+  Future<Result<T>> safeRequest<T>(Future<T> Function(Dio dio) request) async {
+    try {
+      return Success(await request(dio));
+    } on DioException catch (error) {
+      return Error(_mapDioException(error).toFailure());
+    } on AppException catch (error) {
+      return Error(error.toFailure());
+    } catch (error) {
+      return Error(
+          UnknownException(error.toString(), details: error).toFailure());
+    }
+  }
+
+  static AppException _mapDioException(DioException error) {
+    return switch (error.type) {
+      DioExceptionType.connectionTimeout ||
+      DioExceptionType.sendTimeout ||
+      DioExceptionType.receiveTimeout =>
+        RequestTimeoutException('Request timed out', details: error),
+      DioExceptionType.badResponse => BadResponseException(
+          'Provider returned HTTP ${error.response?.statusCode}',
+          details: error,
+        ),
+      DioExceptionType.connectionError => NetworkException(
+          'Network connection failed',
+          details: error,
+        ),
+      _ =>
+        UnknownException(error.message ?? 'Unknown HTTP error', details: error),
+    };
+  }
+}
+
+class _RetryInterceptor extends Interceptor {
+  _RetryInterceptor(this._dio);
+
+  final Dio _dio;
+  static const _maxAttempts = 2;
+
+  @override
+  Future<void> onError(
+      DioException err, ErrorInterceptorHandler handler) async {
+    final attempt = (err.requestOptions.extra['retryAttempt'] as int?) ?? 0;
+    if (!_shouldRetry(err) || attempt >= _maxAttempts) {
+      handler.next(err);
+      return;
+    }
+
+    final delayMs = 350 * pow(2, attempt).toInt();
+    await Future<void>.delayed(Duration(milliseconds: delayMs));
+    try {
+      final options = err.requestOptions;
+      options.extra['retryAttempt'] = attempt + 1;
+      final response = await _dio.fetch<dynamic>(options);
+      handler.resolve(response);
+    } on DioException catch (error) {
+      handler.next(error);
+    }
+  }
+
+  bool _shouldRetry(DioException error) {
+    final status = error.response?.statusCode;
+    return error.type == DioExceptionType.connectionError ||
+        error.type == DioExceptionType.receiveTimeout ||
+        status == 429 ||
+        (status != null && status >= 500);
+  }
+}

lib/core/http/network_info.dart

@@ -0,0 +1,12 @@
+import 'package:connectivity_plus/connectivity_plus.dart';
+
+class NetworkInfo {
+  NetworkInfo(this._connectivity);
+
+  final Connectivity _connectivity;
+
+  Future<bool> get isConnected async {
+    final results = await _connectivity.checkConnectivity();
+    return results.any((result) => result != ConnectivityResult.none);
+  }
+}

lib/core/utils/logger.dart

@@ -0,0 +1,13 @@
+import 'package:flutter/foundation.dart';
+
+class AppLogger {
+  const AppLogger();
+
+  void debug(String message, [Object? error, StackTrace? stackTrace]) {
+    if (kDebugMode) {
+      debugPrint('[GelRule] $message');
+      if (error != null) debugPrint('  error: $error');
+      if (stackTrace != null) debugPrint('  stack: $stackTrace');
+    }
+  }
+}

lib/core/utils/result.dart

@@ -0,0 +1,29 @@
+import '../errors/failure.dart';
+
+sealed class Result<T> {
+  const Result();
+
+  bool get isSuccess => this is Success<T>;
+  bool get isError => this is Error<T>;
+
+  R fold<R>({
+    required R Function(T data) onSuccess,
+    required R Function(Failure failure) onError,
+  }) {
+    final current = this;
+    return switch (current) {
+      Success<T>(:final data) => onSuccess(data),
+      Error<T>(:final failure) => onError(failure),
+    };
+  }
+}
+
+class Success<T> extends Result<T> {
+  const Success(this.data);
+  final T data;
+}
+
+class Error<T> extends Result<T> {
+  const Error(this.failure);
+  final Failure failure;
+}

lib/features/collections/presentation/collection_details_screen.dart

@@ -0,0 +1,51 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:go_router/go_router.dart';
+
+import '../../../app/app.dart';
+import '../../../app/responsive.dart';
+import '../../../backend/backend.dart';
+import '../../../shared/widgets/adaptive_scaffold.dart';
+import '../../../shared/widgets/empty_view.dart';
+import '../../../shared/widgets/error_view.dart';
+import '../../../shared/widgets/post_masonry_grid.dart';
+import 'collections_controller.dart';
+
+class CollectionDetailsScreen extends ConsumerWidget {
+  const CollectionDetailsScreen({required this.collectionId, super.key});
+
+  final String collectionId;
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final posts = ref.watch(collectionPostsProvider(collectionId));
+    final settings =
+        ref.watch(appSettingsProvider).value ?? AppSettings.defaults;
+    return AdaptiveScaffold(
+      title: 'Collection',
+      body: posts.when(
+        loading: () => const Center(child: CircularProgressIndicator()),
+        error: (error, _) => ErrorView(message: error.toString()),
+        data: (items) => items.isEmpty
+            ? const EmptyView(title: 'Collection is empty')
+            : PostMasonryGrid(
+                posts: items,
+                columns: Responsive.columnsFor(
+                  context,
+                  mobileColumns: settings.mobileColumns,
+                  desktopColumns: settings.desktopColumns,
+                ),
+                blurExplicit: settings.blurExplicitContent,
+                showBadges: settings.showPostBadges,
+                nsfwEnabled: settings.nsfwEnabled,
+                onOpen: (post) => context.push(
+                  '/post/${post.providerId}/${post.id}',
+                  extra: post,
+                ),
+                onFavorite: (post) =>
+                    ref.read(favoriteServiceProvider).addFavorite(post),
+              ),
+      ),
+    );
+  }
+}

lib/features/collections/presentation/collection_form_dialog.dart

@@ -0,0 +1,65 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+import '../../../backend/backend.dart';
+import 'collections_controller.dart';
+
+Future<void> showCollectionFormDialog(
+  BuildContext context,
+  WidgetRef ref, {
+  Collection? collection,
+}) async {
+  final nameController = TextEditingController(text: collection?.name);
+  final descriptionController =
+      TextEditingController(text: collection?.description);
+  await showDialog<void>(
+    context: context,
+    builder: (context) => AlertDialog(
+      title: Text(collection == null ? 'New collection' : 'Edit collection'),
+      content: Column(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          TextField(
+            controller: nameController,
+            decoration: const InputDecoration(labelText: 'Name'),
+          ),
+          const SizedBox(height: 12),
+          TextField(
+            controller: descriptionController,
+            decoration: const InputDecoration(labelText: 'Description'),
+          ),
+        ],
+      ),
+      actions: [
+        TextButton(
+          onPressed: () => Navigator.pop(context),
+          child: const Text('Cancel'),
+        ),
+        FilledButton(
+          onPressed: () async {
+            final name = nameController.text.trim();
+            if (name.isEmpty) return;
+            if (collection == null) {
+              await ref
+                  .read(collectionsControllerProvider.notifier)
+                  .create(name, descriptionController.text.trim());
+            } else {
+              await ref
+                  .read(collectionsControllerProvider.notifier)
+                  .updateCollection(
+                    collection.id,
+                    name: name,
+                    description: descriptionController.text.trim(),
+                    coverUrl: collection.coverUrl,
+                  );
+            }
+            if (context.mounted) Navigator.pop(context);
+          },
+          child: const Text('Save'),
+        ),
+      ],
+    ),
+  );
+  nameController.dispose();
+  descriptionController.dispose();
+}

lib/features/collections/presentation/collections_controller.dart

@@ -0,0 +1,54 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+import '../../../backend/backend.dart';
+import '../../../core/utils/result.dart';
+
+final collectionsControllerProvider =
+    AsyncNotifierProvider<CollectionsController, List<Collection>>(
+  CollectionsController.new,
+);
+
+class CollectionsController extends AsyncNotifier<List<Collection>> {
+  @override
+  Future<List<Collection>> build() => _load();
+
+  Future<void> create(String name, String? description) async {
+    await ref
+        .read(collectionServiceProvider)
+        .createCollection(name, description);
+    state = AsyncData(await _load());
+  }
+
+  Future<void> updateCollection(
+    String id, {
+    required String name,
+    String? description,
+    String? coverUrl,
+  }) async {
+    await ref.read(collectionServiceProvider).updateCollection(
+          id,
+          name: name,
+          description: description,
+          coverUrl: coverUrl,
+        );
+    state = AsyncData(await _load());
+  }
+
+  Future<void> delete(String id) async {
+    await ref.read(collectionServiceProvider).deleteCollection(id);
+    state = AsyncData(await _load());
+  }
+
+  Future<List<Collection>> _load() async {
+    final result = await ref.read(collectionServiceProvider).getCollections();
+    return result is Success<List<Collection>> ? result.data : const [];
+  }
+}
+
+final collectionPostsProvider =
+    FutureProvider.family<List<Post>, String>((ref, collectionId) async {
+  final result = await ref
+      .watch(collectionServiceProvider)
+      .getCollectionPosts(collectionId);
+  return result is Success<List<Post>> ? result.data : const [];
+});

lib/features/collections/presentation/collections_screen.dart

@@ -0,0 +1,98 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:go_router/go_router.dart';
+
+import '../../../shared/widgets/adaptive_scaffold.dart';
+import '../../../shared/widgets/confirm_dialog.dart';
+import '../../../shared/widgets/empty_view.dart';
+import '../../../shared/widgets/error_view.dart';
+import 'collection_form_dialog.dart';
+import 'collections_controller.dart';
+
+class CollectionsScreen extends ConsumerWidget {
+  const CollectionsScreen({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final collections = ref.watch(collectionsControllerProvider);
+    return AdaptiveScaffold(
+      title: 'Collections',
+      actions: [
+        IconButton(
+          tooltip: 'New collection',
+          icon: const Icon(Icons.add_rounded),
+          onPressed: () => showCollectionFormDialog(context, ref),
+        ),
+      ],
+      body: collections.when(
+        loading: () => const Center(child: CircularProgressIndicator()),
+        error: (error, _) => ErrorView(message: error.toString()),
+        data: (items) => items.isEmpty
+            ? const EmptyView(title: 'No collections yet')
+            : GridView.builder(
+                padding: const EdgeInsets.all(16),
+                gridDelegate: const SliverGridDelegateWithMaxCrossAxisExtent(
+                  maxCrossAxisExtent: 320,
+                  mainAxisSpacing: 12,
+                  crossAxisSpacing: 12,
+                  childAspectRatio: 1.35,
+                ),
+                itemCount: items.length,
+                itemBuilder: (context, index) {
+                  final item = items[index];
+                  return Card(
+                    clipBehavior: Clip.antiAlias,
+                    child: InkWell(
+                      onTap: () => context.go('/collections/${item.id}'),
+                      child: Padding(
+                        padding: const EdgeInsets.all(16),
+                        child: Column(
+                          crossAxisAlignment: CrossAxisAlignment.start,
+                          children: [
+                            const Icon(Icons.collections_bookmark_rounded,
+                                size: 32),
+                            const Spacer(),
+                            Text(item.name,
+                                style: Theme.of(context).textTheme.titleLarge),
+                            Text(item.description ?? ''),
+                            Row(
+                              children: [
+                                IconButton(
+                                  tooltip: 'Edit',
+                                  onPressed: () => showCollectionFormDialog(
+                                    context,
+                                    ref,
+                                    collection: item,
+                                  ),
+                                  icon: const Icon(Icons.edit_rounded),
+                                ),
+                                IconButton(
+                                  tooltip: 'Delete',
+                                  onPressed: () async {
+                                    final ok = await showConfirmDialog(
+                                      context,
+                                      title: 'Delete collection',
+                                      message: 'Remove ${item.name}?',
+                                    );
+                                    if (ok) {
+                                      await ref
+                                          .read(collectionsControllerProvider
+                                              .notifier)
+                                          .delete(item.id);
+                                    }
+                                  },
+                                  icon: const Icon(Icons.delete_rounded),
+                                ),
+                              ],
+                            ),
+                          ],
+                        ),
+                      ),
+                    ),
+                  );
+                },
+              ),
+      ),
+    );
+  }
+}

lib/features/favorites/presentation/favorites_controller.dart

@@ -0,0 +1,27 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+import '../../../backend/backend.dart';
+import '../../../core/utils/result.dart';
+import 'favorites_state.dart';
+
+final favoritesControllerProvider =
+    AsyncNotifierProvider<FavoritesController, FavoritesState>(
+  FavoritesController.new,
+);
+
+class FavoritesController extends AsyncNotifier<FavoritesState> {
+  @override
+  Future<FavoritesState> build() async => FavoritesState(posts: await _load());
+
+  Future<void> remove(Post post) async {
+    await ref
+        .read(favoriteServiceProvider)
+        .removeFavorite(post.id, post.providerId);
+    state = AsyncData(FavoritesState(posts: await _load()));
+  }
+
+  Future<List<Post>> _load() async {
+    final result = await ref.read(favoriteServiceProvider).getFavoritePosts();
+    return result is Success<List<Post>> ? result.data : const [];
+  }
+}

lib/features/favorites/presentation/favorites_screen.dart

@@ -0,0 +1,49 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:go_router/go_router.dart';
+
+import '../../../app/app.dart';
+import '../../../app/responsive.dart';
+import '../../../backend/backend.dart';
+import '../../../shared/widgets/adaptive_scaffold.dart';
+import '../../../shared/widgets/empty_view.dart';
+import '../../../shared/widgets/error_view.dart';
+import '../../../shared/widgets/post_masonry_grid.dart';
+import 'favorites_controller.dart';
+
+class FavoritesScreen extends ConsumerWidget {
+  const FavoritesScreen({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final state = ref.watch(favoritesControllerProvider);
+    final settings =
+        ref.watch(appSettingsProvider).value ?? AppSettings.defaults;
+    return AdaptiveScaffold(
+      title: 'Favorites',
+      body: state.when(
+        loading: () => const Center(child: CircularProgressIndicator()),
+        error: (error, _) => ErrorView(message: error.toString()),
+        data: (data) => data.posts.isEmpty
+            ? const EmptyView(title: 'No favorites yet')
+            : PostMasonryGrid(
+                posts: data.posts,
+                columns: Responsive.columnsFor(
+                  context,
+                  mobileColumns: settings.mobileColumns,
+                  desktopColumns: settings.desktopColumns,
+                ),
+                blurExplicit: settings.blurExplicitContent,
+                showBadges: settings.showPostBadges,
+                nsfwEnabled: settings.nsfwEnabled,
+                onOpen: (post) => context.push(
+                  '/post/${post.providerId}/${post.id}',
+                  extra: post,
+                ),
+                onFavorite: (post) =>
+                    ref.read(favoritesControllerProvider.notifier).remove(post),
+              ),
+      ),
+    );
+  }
+}

lib/features/favorites/presentation/favorites_state.dart

@@ -0,0 +1,6 @@
+import '../../../backend/backend.dart';
+
+class FavoritesState {
+  const FavoritesState({this.posts = const []});
+  final List<Post> posts;
+}

lib/features/feed/presentation/feed_controller.dart

@@ -0,0 +1,170 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+import '../../../backend/backend.dart';
+import '../../../core/utils/result.dart';
+import 'feed_state.dart';
+
+final feedControllerProvider =
+    AsyncNotifierProvider<FeedController, FeedState>(FeedController.new);
+
+class FeedController extends AsyncNotifier<FeedState> {
+  @override
+  Future<FeedState> build() async {
+    final providers = await _loadProviders();
+    final settings = await _settings();
+    final providerIds = providers.map((provider) => provider.id).toSet();
+    final initial = FeedState(
+      providers: providers,
+      ratingFilter: settings.defaultRatingFilter,
+      topPeriodFilter: TopPeriodFilter.values.firstWhere(
+        (value) => value.name == settings.defaultTopPeriodFilter,
+        orElse: () => TopPeriodFilter.none,
+      ),
+      selectedProviderIds:
+          settings.selectedFeedProviderIds.where(providerIds.contains).toList(),
+    );
+    state = AsyncData(initial);
+    await loadInitial();
+    return state.value ?? initial;
+  }
+
+  Future<void> loadInitial() async {
+    final current = state.value ?? const FeedState();
+    state = const AsyncLoading();
+    final posts = await _load(refresh: true, current: current);
+    state = AsyncData(current.copyWith(posts: posts, clearError: true));
+  }
+
+  Future<void> refresh() async {
+    final current = state.value ?? const FeedState();
+    state = AsyncData(current.copyWith(isLoadingMore: true, clearError: true));
+    final posts = await _load(refresh: true, current: current);
+    state = AsyncData(current.copyWith(posts: posts, isLoadingMore: false));
+  }
+
+  Future<void> loadNextPage() async {
+    final current = state.value;
+    if (current == null || current.isLoadingMore || !current.hasMore) return;
+    state = AsyncData(current.copyWith(isLoadingMore: true, clearError: true));
+    final posts = await _load(refresh: false, current: current);
+    state = AsyncData(
+      current.copyWith(
+        posts: [...current.posts, ...posts],
+        isLoadingMore: false,
+        hasMore: posts.isNotEmpty,
+      ),
+    );
+  }
+
+  Future<void> search(String query) async {
+    final tags = ref.read(searchServiceProvider).parseTags(query);
+    final current = state.value ?? const FeedState();
+    state = AsyncData(current.copyWith(selectedTags: tags, posts: []));
+    await ref.read(searchServiceProvider).saveSearch(query, 0);
+    await refresh();
+    final count = state.value?.posts.length ?? 0;
+    await ref.read(searchServiceProvider).saveSearch(query, count);
+  }
+
+  Future<void> updateTagSuggestions(String query) async {
+    final current = state.value ?? const FeedState();
+    if (query.trim().isEmpty) {
+      state = AsyncData(current.copyWith(tagSuggestions: []));
+      return;
+    }
+    final lastToken = query.trim().split(RegExp(r'\s+')).last;
+    final result =
+        await ref.read(searchServiceProvider).autocomplete(lastToken);
+    final suggestions =
+        result is Success<List<String>> ? result.data : const <String>[];
+    state = AsyncData(current.copyWith(tagSuggestions: suggestions));
+  }
+
+  Future<void> setProviders(List<String> providerIds) async {
+    final current = state.value ?? const FeedState();
+    state = AsyncData(
+        current.copyWith(selectedProviderIds: providerIds, posts: []));
+    final settings = await _settings();
+    await ref.read(settingsServiceProvider).updateSettings(
+        settings.copyWith(selectedFeedProviderIds: providerIds));
+    await refresh();
+  }
+
+  Future<void> setTopPeriod(TopPeriodFilter period) async {
+    final current = state.value ?? const FeedState();
+    state = AsyncData(current.copyWith(topPeriodFilter: period, posts: []));
+    final settings = await _settings();
+    await ref.read(settingsServiceProvider).updateSettings(
+          settings.copyWith(defaultTopPeriodFilter: period.name),
+        );
+    await refresh();
+  }
+
+  Future<void> setRating(String? rating) async {
+    final current = state.value ?? const FeedState();
+    state = AsyncData(
+      current.copyWith(
+          ratingFilter: rating, clearRating: rating == null, posts: []),
+    );
+    await refresh();
+  }
+
+  Future<void> clearFilters() async {
+    final current = state.value ?? const FeedState();
+    state = AsyncData(
+      current.copyWith(
+        selectedTags: [],
+        selectedProviderIds: [],
+        tagSuggestions: [],
+        clearRating: true,
+        posts: [],
+      ),
+    );
+    final settings = await _settings();
+    await ref
+        .read(settingsServiceProvider)
+        .updateSettings(settings.copyWith(selectedFeedProviderIds: []));
+    await refresh();
+  }
+
+  Future<List<Post>> _load({
+    required bool refresh,
+    required FeedState current,
+  }) async {
+    final service = ref.read(feedServiceProvider);
+    final providerIds = current.selectedProviderIds.isEmpty
+        ? <String?>[null]
+        : current.selectedProviderIds;
+    final posts = <Post>[];
+    for (final providerId in providerIds) {
+      final result = refresh
+          ? await service.refresh(
+              tags: current.selectedTags,
+              rating: current.ratingFilter,
+              providerId: providerId,
+              topPeriod: current.topPeriodFilter,
+            )
+          : await service.loadNextPage(
+              tags: current.selectedTags,
+              rating: current.ratingFilter,
+              providerId: providerId,
+              topPeriod: current.topPeriodFilter,
+            );
+      if (result is Success<List<Post>>) posts.addAll(result.data);
+    }
+    return posts;
+  }
+
+  Future<List<ContentProviderConfig>> _loadProviders() async {
+    final result =
+        await ref.read(providerManagerProvider).loadConfigs(enabledOnly: true);
+    return result is Success<List<ContentProviderConfig>>
+        ? result.data
+        : const [];
+  }
+
+  Future<AppSettings> _settings() async {
+    final result = await ref.read(settingsServiceProvider).getSettings();
+    return result is Success<AppSettings> ? result.data : AppSettings.defaults;
+  }
+}

lib/features/feed/presentation/feed_screen.dart

@@ -0,0 +1,209 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:go_router/go_router.dart';
+
+import '../../../app/app.dart';
+import '../../../app/responsive.dart';
+import '../../../backend/backend.dart';
+import '../../../core/utils/result.dart';
+import '../../../shared/widgets/adaptive_scaffold.dart';
+import '../../../shared/widgets/empty_view.dart';
+import '../../../shared/widgets/error_view.dart';
+import '../../../shared/widgets/post_card.dart';
+import '../../../shared/widgets/post_masonry_grid.dart';
+import '../../collections/presentation/collection_form_dialog.dart';
+import 'feed_controller.dart';
+import 'widgets/feed_toolbar.dart';
+
+class FeedScreen extends ConsumerStatefulWidget {
+  const FeedScreen({this.initialQuery, super.key});
+
+  final String? initialQuery;
+
+  @override
+  ConsumerState<FeedScreen> createState() => _FeedScreenState();
+}
+
+class _FeedScreenState extends ConsumerState<FeedScreen> {
+  final _scrollController = ScrollController();
+  bool _usedInitialQuery = false;
+
+  @override
+  void initState() {
+    super.initState();
+    _scrollController.addListener(() {
+      if (_scrollController.position.extentAfter < 800) {
+        ref.read(feedControllerProvider.notifier).loadNextPage();
+      }
+    });
+  }
+
+  @override
+  void dispose() {
+    _scrollController.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final feed = ref.watch(feedControllerProvider);
+    final settings =
+        ref.watch(appSettingsProvider).value ?? AppSettings.defaults;
+
+    if (!_usedInitialQuery && (widget.initialQuery?.isNotEmpty ?? false)) {
+      _usedInitialQuery = true;
+      WidgetsBinding.instance.addPostFrameCallback((_) {
+        ref.read(feedControllerProvider.notifier).search(widget.initialQuery!);
+      });
+    }
+
+    return Shortcuts(
+      shortcuts: {
+        LogicalKeySet(LogicalKeyboardKey.keyR): const _RefreshIntent(),
+      },
+      child: Actions(
+        actions: {
+          _RefreshIntent: CallbackAction<_RefreshIntent>(
+            onInvoke: (_) {
+              ref.read(feedControllerProvider.notifier).refresh();
+              return null;
+            },
+          ),
+        },
+        child: AdaptiveScaffold(
+          title: 'Feed',
+          body: feed.when(
+            loading: () => const Center(child: CircularProgressIndicator()),
+            error: (error, _) => ErrorView(
+              message: error.toString(),
+              onRetry: () =>
+                  ref.read(feedControllerProvider.notifier).loadInitial(),
+            ),
+            data: (state) => Column(
+              children: [
+                FeedToolbar(
+                  selectedTags: state.selectedTags,
+                  selectedProviderIds: state.selectedProviderIds,
+                  topPeriodFilter: state.topPeriodFilter,
+                  tagSuggestions: state.tagSuggestions,
+                  providers: state.providers,
+                  rating: state.ratingFilter,
+                  onSearchChanged: (query) => ref
+                      .read(feedControllerProvider.notifier)
+                      .updateTagSuggestions(query),
+                  onSuggestionTap: (query) =>
+                      ref.read(feedControllerProvider.notifier).search(query),
+                  onTopPeriodChanged: (period) => ref
+                      .read(feedControllerProvider.notifier)
+                      .setTopPeriod(period),
+                  onSearch: (query) =>
+                      ref.read(feedControllerProvider.notifier).search(query),
+                  onRefresh: () =>
+                      ref.read(feedControllerProvider.notifier).refresh(),
+                  onClearFilters: () =>
+                      ref.read(feedControllerProvider.notifier).clearFilters(),
+                  onQuickProviderToggle: (providerId) {
+                    if (providerId == '__all__') {
+                      ref
+                          .read(feedControllerProvider.notifier)
+                          .setProviders([]);
+                      return;
+                    }
+                    final selected =
+                        state.selectedProviderIds.contains(providerId)
+                            ? state.selectedProviderIds
+                                .where((id) => id != providerId)
+                                .toList()
+                            : [...state.selectedProviderIds, providerId];
+                    ref
+                        .read(feedControllerProvider.notifier)
+                        .setProviders(selected);
+                  },
+                  onProviderFilter: () async {
+                    final selected = await showProviderFilterSheet(
+                      context,
+                      providers: state.providers,
+                      selectedIds: state.selectedProviderIds,
+                    );
+                    if (selected != null) {
+                      await ref
+                          .read(feedControllerProvider.notifier)
+                          .setProviders(selected);
+                    }
+                  },
+                  onRatingFilter: () async {
+                    final rating = await showRatingFilterSheet(
+                        context, state.ratingFilter);
+                    await ref
+                        .read(feedControllerProvider.notifier)
+                        .setRating(rating);
+                  },
+                ),
+                Expanded(
+                  child: state.posts.isEmpty && !state.isLoadingMore
+                      ? const EmptyView(
+                          title: 'No posts yet',
+                          message: 'Try another tag or check providers.',
+                        )
+                      : RefreshIndicator(
+                          onRefresh: () => ref
+                              .read(feedControllerProvider.notifier)
+                              .refresh(),
+                          child: PostMasonryGrid(
+                            controller: _scrollController,
+                            posts: state.posts,
+                            columns: Responsive.columnsFor(
+                              context,
+                              mobileColumns: settings.mobileColumns,
+                              desktopColumns: settings.desktopColumns,
+                            ),
+                            blurExplicit: settings.blurExplicitContent,
+                            showBadges: settings.showPostBadges,
+                            nsfwEnabled: settings.nsfwEnabled,
+                            loading: state.isLoadingMore,
+                            onOpen: (post) => context.push(
+                              '/post/${post.providerId}/${post.id}',
+                              extra: post,
+                            ),
+                            onFavorite: (post) => ref
+                                .read(favoriteServiceProvider)
+                                .addFavorite(post),
+                            onAddToCollection: (post) =>
+                                _addToCollection(context, ref, post),
+                          ),
+                        ),
+                ),
+              ],
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+
+  Future<void> _addToCollection(
+    BuildContext context,
+    WidgetRef ref,
+    Post post,
+  ) async {
+    final result = await ref.read(collectionServiceProvider).getCollections();
+    final collections =
+        result is Success<List<Collection>> ? result.data : <Collection>[];
+    if (!context.mounted) return;
+    await showAddToCollectionPicker(
+      context,
+      collections: collections,
+      onSelected: (collection) {
+        ref
+            .read(collectionServiceProvider)
+            .addPostToCollection(collection.id, post);
+      },
+      onCreate: () => showCollectionFormDialog(context, ref),
+    );
+  }
+}
+
+class _RefreshIntent extends Intent {
+  const _RefreshIntent();
+}

lib/features/feed/presentation/feed_state.dart

@@ -0,0 +1,55 @@
+import '../../../backend/backend.dart';
+
+class FeedState {
+  const FeedState({
+    this.posts = const [],
+    this.selectedTags = const [],
+    this.selectedProviderIds = const [],
+    this.ratingFilter,
+    this.topPeriodFilter = TopPeriodFilter.none,
+    this.tagSuggestions = const [],
+    this.providers = const [],
+    this.isLoadingMore = false,
+    this.hasMore = true,
+    this.error,
+  });
+
+  final List<Post> posts;
+  final List<String> selectedTags;
+  final List<String> selectedProviderIds;
+  final String? ratingFilter;
+  final TopPeriodFilter topPeriodFilter;
+  final List<String> tagSuggestions;
+  final List<ContentProviderConfig> providers;
+  final bool isLoadingMore;
+  final bool hasMore;
+  final String? error;
+
+  FeedState copyWith({
+    List<Post>? posts,
+    List<String>? selectedTags,
+    List<String>? selectedProviderIds,
+    String? ratingFilter,
+    TopPeriodFilter? topPeriodFilter,
+    List<String>? tagSuggestions,
+    bool clearRating = false,
+    List<ContentProviderConfig>? providers,
+    bool? isLoadingMore,
+    bool? hasMore,
+    String? error,
+    bool clearError = false,
+  }) {
+    return FeedState(
+      posts: posts ?? this.posts,
+      selectedTags: selectedTags ?? this.selectedTags,
+      selectedProviderIds: selectedProviderIds ?? this.selectedProviderIds,
+      ratingFilter: clearRating ? null : ratingFilter ?? this.ratingFilter,
+      topPeriodFilter: topPeriodFilter ?? this.topPeriodFilter,
+      tagSuggestions: tagSuggestions ?? this.tagSuggestions,
+      providers: providers ?? this.providers,
+      isLoadingMore: isLoadingMore ?? this.isLoadingMore,
+      hasMore: hasMore ?? this.hasMore,
+      error: clearError ? null : error ?? this.error,
+    );
+  }
+}

lib/features/feed/presentation/widgets/feed_toolbar.dart

@@ -0,0 +1,356 @@
+import 'package:flutter/material.dart';
+
+import '../../../../app/responsive.dart';
+import '../../../../backend/backend.dart';
+import '../../../../shared/widgets/app_search_bar.dart';
+
+class FeedToolbar extends StatefulWidget {
+  const FeedToolbar({
+    required this.onSearch,
+    required this.onRefresh,
+    required this.onProviderFilter,
+    required this.onRatingFilter,
+    required this.onClearFilters,
+    required this.providers,
+    required this.selectedTags,
+    required this.selectedProviderIds,
+    required this.topPeriodFilter,
+    required this.tagSuggestions,
+    required this.rating,
+    required this.onQuickProviderToggle,
+    required this.onSearchChanged,
+    required this.onSuggestionTap,
+    required this.onTopPeriodChanged,
+    super.key,
+  });
+
+  final ValueChanged<String> onSearch;
+  final VoidCallback onRefresh;
+  final VoidCallback onProviderFilter;
+  final VoidCallback onRatingFilter;
+  final VoidCallback onClearFilters;
+  final List<ContentProviderConfig> providers;
+  final List<String> selectedTags;
+  final List<String> selectedProviderIds;
+  final TopPeriodFilter topPeriodFilter;
+  final List<String> tagSuggestions;
+  final String? rating;
+  final ValueChanged<String> onQuickProviderToggle;
+  final ValueChanged<String> onSearchChanged;
+  final ValueChanged<String> onSuggestionTap;
+  final ValueChanged<TopPeriodFilter> onTopPeriodChanged;
+
+  @override
+  State<FeedToolbar> createState() => _FeedToolbarState();
+}
+
+class _FeedToolbarState extends State<FeedToolbar> {
+  late String _query;
+
+  @override
+  void initState() {
+    super.initState();
+    _query = widget.selectedTags.join(' ');
+  }
+
+  @override
+  void didUpdateWidget(covariant FeedToolbar oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    if (oldWidget.selectedTags != widget.selectedTags) {
+      _query = widget.selectedTags.join(' ');
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    if (Responsive.isMobile(context)) return _buildMobile(context);
+    return _buildDesktop(context);
+  }
+
+  Widget _buildDesktop(BuildContext context) {
+    return Padding(
+      padding: const EdgeInsets.fromLTRB(16, 12, 16, 8),
+      child: Column(
+        children: [
+          Row(
+            children: [
+              Expanded(
+                child: AppSearchBar(
+                  initialValue: _query,
+                  onChanged: (value) {
+                    _query = value;
+                    widget.onSearchChanged(value);
+                  },
+                  onSubmitted: widget.onSearch,
+                ),
+              ),
+              const SizedBox(width: 8),
+              IconButton.filledTonal(
+                tooltip: 'Providers',
+                onPressed: widget.onProviderFilter,
+                icon: const Icon(Icons.hub_rounded),
+              ),
+              IconButton.filledTonal(
+                tooltip: 'Rating',
+                onPressed: widget.onRatingFilter,
+                icon: const Icon(Icons.tune_rounded),
+              ),
+              IconButton(
+                tooltip: 'Clear filters',
+                onPressed: widget.onClearFilters,
+                icon: const Icon(Icons.filter_alt_off_rounded),
+              ),
+              IconButton(
+                tooltip: 'Refresh',
+                onPressed: widget.onRefresh,
+                icon: const Icon(Icons.refresh_rounded),
+              ),
+            ],
+          ),
+          const SizedBox(height: 8),
+          SizedBox(
+            height: 36,
+            child: ListView(
+              scrollDirection: Axis.horizontal,
+              children: [
+                if (widget.providers.isNotEmpty) ...[
+                  FilterChip(
+                    selected: widget.selectedProviderIds.isEmpty,
+                    label: const Text('All providers'),
+                    onSelected: (_) => widget.onQuickProviderToggle('__all__'),
+                  ),
+                  const SizedBox(width: 8),
+                  for (final provider in widget.providers) ...[
+                    FilterChip(
+                      selected:
+                          widget.selectedProviderIds.contains(provider.id),
+                      avatar: const Icon(Icons.hub_rounded, size: 16),
+                      label: Text(provider.name),
+                      onSelected: (_) =>
+                          widget.onQuickProviderToggle(provider.id),
+                    ),
+                    const SizedBox(width: 8),
+                  ],
+                  const SizedBox(width: 8),
+                ],
+                for (final period in TopPeriodFilter.values) ...[
+                  ChoiceChip(
+                    selected: widget.topPeriodFilter == period,
+                    label: Text(period.label),
+                    onSelected: (_) => widget.onTopPeriodChanged(period),
+                  ),
+                  const SizedBox(width: 8),
+                ],
+              ],
+            ),
+          ),
+          if (widget.tagSuggestions.isNotEmpty) ...[
+            const SizedBox(height: 8),
+            SizedBox(
+              height: 34,
+              child: ListView.separated(
+                scrollDirection: Axis.horizontal,
+                itemCount: widget.tagSuggestions.length,
+                separatorBuilder: (_, __) => const SizedBox(width: 8),
+                itemBuilder: (context, index) => ActionChip(
+                  avatar: const Icon(Icons.tag_rounded, size: 15),
+                  label: Text(widget.tagSuggestions[index]),
+                  onPressed: () =>
+                      _applySuggestion(widget.tagSuggestions[index]),
+                ),
+              ),
+            ),
+          ],
+        ],
+      ),
+    );
+  }
+
+  Widget _buildMobile(BuildContext context) {
+    return Padding(
+      padding: const EdgeInsets.fromLTRB(8, 6, 8, 6),
+      child: Column(
+        children: [
+          AppSearchBar(
+            initialValue: _query,
+            onChanged: (value) {
+              _query = value;
+              widget.onSearchChanged(value);
+            },
+            onSubmitted: widget.onSearch,
+          ),
+          const SizedBox(height: 8),
+          SizedBox(
+            height: 40,
+            child: ListView(
+              scrollDirection: Axis.horizontal,
+              children: [
+                IconButton.filledTonal(
+                  tooltip: 'Providers',
+                  onPressed: widget.onProviderFilter,
+                  icon: const Icon(Icons.hub_rounded),
+                ),
+                const SizedBox(width: 6),
+                IconButton.filledTonal(
+                  tooltip: 'Rating',
+                  onPressed: widget.onRatingFilter,
+                  icon: const Icon(Icons.tune_rounded),
+                ),
+                const SizedBox(width: 6),
+                IconButton(
+                  tooltip: 'Clear filters',
+                  onPressed: widget.onClearFilters,
+                  icon: const Icon(Icons.filter_alt_off_rounded),
+                ),
+                IconButton(
+                  tooltip: 'Refresh',
+                  onPressed: widget.onRefresh,
+                  icon: const Icon(Icons.refresh_rounded),
+                ),
+                const SizedBox(width: 8),
+                if (widget.providers.isNotEmpty) ...[
+                  FilterChip(
+                    selected: widget.selectedProviderIds.isEmpty,
+                    label: const Text('All'),
+                    onSelected: (_) => widget.onQuickProviderToggle('__all__'),
+                  ),
+                  const SizedBox(width: 6),
+                  for (final provider in widget.providers) ...[
+                    FilterChip(
+                      selected:
+                          widget.selectedProviderIds.contains(provider.id),
+                      label: Text(provider.name),
+                      onSelected: (_) =>
+                          widget.onQuickProviderToggle(provider.id),
+                    ),
+                    const SizedBox(width: 6),
+                  ],
+                ],
+              ],
+            ),
+          ),
+          const SizedBox(height: 6),
+          SizedBox(
+            height: 36,
+            child: ListView(
+              scrollDirection: Axis.horizontal,
+              children: [
+                for (final period in TopPeriodFilter.values) ...[
+                  ChoiceChip(
+                    selected: widget.topPeriodFilter == period,
+                    label: Text(period.label),
+                    onSelected: (_) => widget.onTopPeriodChanged(period),
+                  ),
+                  const SizedBox(width: 6),
+                ],
+              ],
+            ),
+          ),
+          if (widget.tagSuggestions.isNotEmpty) ...[
+            const SizedBox(height: 6),
+            SizedBox(
+              height: 34,
+              child: ListView.separated(
+                scrollDirection: Axis.horizontal,
+                itemCount: widget.tagSuggestions.length,
+                separatorBuilder: (_, __) => const SizedBox(width: 6),
+                itemBuilder: (context, index) => ActionChip(
+                  label: Text(widget.tagSuggestions[index]),
+                  onPressed: () =>
+                      _applySuggestion(widget.tagSuggestions[index]),
+                ),
+              ),
+            ),
+          ],
+        ],
+      ),
+    );
+  }
+
+  void _applySuggestion(String suggestion) {
+    final tokens = _query.trim().isEmpty
+        ? <String>[]
+        : _query.trim().split(RegExp(r'\s+'));
+    if (tokens.isEmpty) {
+      tokens.add(suggestion);
+    } else {
+      tokens[tokens.length - 1] = suggestion;
+    }
+    final next = tokens.toSet().join(' ');
+    setState(() => _query = next);
+    widget.onSuggestionTap(next);
+  }
+}
+
+Future<List<String>?> showProviderFilterSheet(
+  BuildContext context, {
+  required List<ContentProviderConfig> providers,
+  required List<String> selectedIds,
+}) {
+  final selected = selectedIds.toSet();
+  return showModalBottomSheet<List<String>>(
+    context: context,
+    showDragHandle: true,
+    builder: (context) => StatefulBuilder(
+      builder: (context, setState) => ListView(
+        padding: const EdgeInsets.all(16),
+        children: [
+          Text('Providers', style: Theme.of(context).textTheme.titleLarge),
+          const SizedBox(height: 8),
+          for (final provider in providers)
+            CheckboxListTile(
+              value: selected.contains(provider.id),
+              title: Text(provider.name),
+              subtitle: Text(provider.baseUrl),
+              onChanged: (value) {
+                setState(() {
+                  if (value ?? false) {
+                    selected.add(provider.id);
+                  } else {
+                    selected.remove(provider.id);
+                  }
+                });
+              },
+            ),
+          const SizedBox(height: 12),
+          FilledButton(
+            onPressed: () => Navigator.pop(context, selected.toList()),
+            child: const Text('Apply'),
+          ),
+        ],
+      ),
+    ),
+  );
+}
+
+Future<String?> showRatingFilterSheet(BuildContext context, String? selected) {
+  return showModalBottomSheet<String?>(
+    context: context,
+    showDragHandle: true,
+    builder: (context) => ListView(
+      padding: const EdgeInsets.all(16),
+      children: [
+        Text('Rating', style: Theme.of(context).textTheme.titleLarge),
+        ListTile(
+          leading: Icon(
+            selected == null
+                ? Icons.radio_button_checked_rounded
+                : Icons.radio_button_off_rounded,
+          ),
+          title: const Text('Any'),
+          onTap: () => Navigator.pop(context, null),
+        ),
+        for (final rating in ['safe', 'questionable', 'explicit'])
+          ListTile(
+            leading: Icon(
+              selected == rating
+                  ? Icons.radio_button_checked_rounded
+                  : Icons.radio_button_off_rounded,
+            ),
+            title: Text(rating),
+            onTap: () => Navigator.pop(context, rating),
+          ),
+      ],
+    ),
+  );
+}

lib/features/feed/presentation/widgets/provider_filter_sheet.dart

@@ -0,0 +1 @@
+export 'feed_toolbar.dart' show showProviderFilterSheet;

lib/features/feed/presentation/widgets/rating_filter_sheet.dart

@@ -0,0 +1 @@
+export 'feed_toolbar.dart' show showRatingFilterSheet;

lib/features/post/presentation/post_details_controller.dart

@@ -0,0 +1,40 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+import '../../../backend/backend.dart';
+import '../../../core/utils/result.dart';
+
+final postDetailsControllerProvider =
+    FutureProvider.family<Post?, PostDetailsArgs>((ref, args) async {
+  if (args.initialPost != null) return args.initialPost;
+  final cached = await ref
+      .watch(postRepositoryProvider)
+      .getCachedPost(args.postId, args.providerId);
+  if (cached is Success<Post?> && cached.data != null) return cached.data;
+  final remote = await ref
+      .watch(providerManagerProvider)
+      .getPost(args.providerId, args.postId);
+  return remote is Success<Post?> ? remote.data : null;
+});
+
+class PostDetailsArgs {
+  const PostDetailsArgs({
+    required this.providerId,
+    required this.postId,
+    this.initialPost,
+  });
+
+  final String providerId;
+  final String postId;
+  final Post? initialPost;
+
+  @override
+  bool operator ==(Object other) {
+    return other is PostDetailsArgs &&
+        other.providerId == providerId &&
+        other.postId == postId &&
+        other.initialPost == initialPost;
+  }
+
+  @override
+  int get hashCode => Object.hash(providerId, postId, initialPost);
+}

lib/features/post/presentation/post_details_screen.dart

@@ -0,0 +1,245 @@
+import 'package:dio/dio.dart';
+import 'package:file_selector/file_selector.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:go_router/go_router.dart';
+import 'package:path/path.dart' as p;
+import 'package:url_launcher/url_launcher.dart';
+
+import '../../../app/app.dart';
+import '../../../app/responsive.dart';
+import '../../../backend/backend.dart';
+import '../../../core/utils/result.dart';
+import '../../../shared/widgets/adaptive_scaffold.dart';
+import '../../../shared/widgets/empty_view.dart';
+import '../../../shared/widgets/error_view.dart';
+import '../../../shared/widgets/post_card.dart';
+import '../../../shared/widgets/rating_badge.dart';
+import '../../collections/presentation/collection_form_dialog.dart';
+import '../../feed/presentation/feed_controller.dart';
+import 'post_details_controller.dart';
+import 'widgets/post_action_bar.dart';
+import 'widgets/post_media_viewer.dart';
+import 'widgets/post_tags_panel.dart';
+
+class PostDetailsScreen extends ConsumerWidget {
+  const PostDetailsScreen({
+    required this.providerId,
+    required this.postId,
+    this.initialPost,
+    super.key,
+  });
+
+  final String providerId;
+  final String postId;
+  final Post? initialPost;
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final args = PostDetailsArgs(
+      providerId: providerId,
+      postId: postId,
+      initialPost: initialPost,
+    );
+    final post = ref.watch(postDetailsControllerProvider(args));
+    final settings =
+        ref.watch(appSettingsProvider).value ?? AppSettings.defaults;
+    final feedPosts =
+        ref.watch(feedControllerProvider).value?.posts ?? const <Post>[];
+    return AdaptiveScaffold(
+      title: 'Post',
+      actions: [
+        IconButton(
+          tooltip: 'Close',
+          onPressed: () => _close(context),
+          icon: const Icon(Icons.close_rounded),
+        ),
+      ],
+      body: post.when(
+        loading: () => const Center(child: CircularProgressIndicator()),
+        error: (error, _) => ErrorView(message: error.toString()),
+        data: (post) {
+          if (post == null) return const EmptyView(title: 'Post not found');
+          final currentIndex = feedPosts.indexWhere(
+            (item) => item.providerId == post.providerId && item.id == post.id,
+          );
+          final previous =
+              currentIndex > 0 ? feedPosts[currentIndex - 1] : null;
+          final next = currentIndex >= 0 && currentIndex < feedPosts.length - 1
+              ? feedPosts[currentIndex + 1]
+              : null;
+          if (Responsive.isMobile(context)) {
+            return _buildMobileDetails(context, ref, post, settings);
+          }
+          return ListView(
+            padding: const EdgeInsets.all(16),
+            children: [
+              Row(
+                crossAxisAlignment: CrossAxisAlignment.center,
+                children: [
+                  IconButton.filledTonal(
+                    tooltip: 'Previous',
+                    onPressed: previous == null
+                        ? null
+                        : () => _openPost(context, previous),
+                    icon: const Icon(Icons.chevron_left_rounded),
+                  ),
+                  Expanded(
+                    child: Center(
+                      child: ConstrainedBox(
+                        constraints: const BoxConstraints(maxHeight: 760),
+                        child: PostMediaViewer(post: post),
+                      ),
+                    ),
+                  ),
+                  IconButton.filledTonal(
+                    tooltip: 'Next',
+                    onPressed:
+                        next == null ? null : () => _openPost(context, next),
+                    icon: const Icon(Icons.chevron_right_rounded),
+                  ),
+                ],
+              ),
+              const SizedBox(height: 16),
+              PostActionBar(
+                onFavorite: () =>
+                    ref.read(favoriteServiceProvider).addFavorite(post),
+                onCollection: () => _addToCollection(context, ref, post),
+                onOpen: () => launchUrl(Uri.parse(post.fileUrl)),
+                onCopy: () =>
+                    Clipboard.setData(ClipboardData(text: post.fileUrl)),
+                onDownload: settings.allowDownloads
+                    ? () => _download(context, post)
+                    : null,
+              ),
+              const SizedBox(height: 16),
+              Wrap(
+                spacing: 8,
+                runSpacing: 8,
+                crossAxisAlignment: WrapCrossAlignment.center,
+                children: [
+                  Chip(label: Text(post.providerName)),
+                  RatingBadge(rating: post.rating),
+                  Chip(label: Text('${post.width} x ${post.height}')),
+                  if (post.source != null && post.source!.isNotEmpty)
+                    ActionChip(
+                      label: const Text('Source'),
+                      onPressed: () => launchUrl(Uri.parse(post.source!)),
+                    ),
+                ],
+              ),
+              const SizedBox(height: 16),
+              Text('Tags', style: Theme.of(context).textTheme.titleLarge),
+              const SizedBox(height: 8),
+              PostTagsPanel(post: post),
+            ],
+          );
+        },
+      ),
+    );
+  }
+
+  Widget _buildMobileDetails(
+    BuildContext context,
+    WidgetRef ref,
+    Post post,
+    AppSettings settings,
+  ) {
+    return ListView(
+      padding: const EdgeInsets.fromLTRB(8, 8, 8, 16),
+      children: [
+        ConstrainedBox(
+          constraints: BoxConstraints(
+            maxHeight: MediaQuery.sizeOf(context).height * 0.62,
+          ),
+          child: Center(child: PostMediaViewer(post: post)),
+        ),
+        const SizedBox(height: 12),
+        PostActionBar(
+          onFavorite: () => ref.read(favoriteServiceProvider).addFavorite(post),
+          onCollection: () => _addToCollection(context, ref, post),
+          onOpen: () => launchUrl(Uri.parse(post.fileUrl)),
+          onCopy: () => Clipboard.setData(ClipboardData(text: post.fileUrl)),
+          onDownload:
+              settings.allowDownloads ? () => _download(context, post) : null,
+        ),
+        const SizedBox(height: 12),
+        Wrap(
+          spacing: 8,
+          runSpacing: 8,
+          children: [
+            Chip(label: Text(post.providerName)),
+            RatingBadge(rating: post.rating),
+            Chip(label: Text('${post.width} x ${post.height}')),
+            if (post.source != null && post.source!.isNotEmpty)
+              ActionChip(
+                label: const Text('Source'),
+                onPressed: () => launchUrl(Uri.parse(post.source!)),
+              ),
+          ],
+        ),
+        const SizedBox(height: 8),
+        ExpansionTile(
+          tilePadding: EdgeInsets.zero,
+          initiallyExpanded: false,
+          title: Text('Tags', style: Theme.of(context).textTheme.titleMedium),
+          children: [
+            Align(
+              alignment: Alignment.centerLeft,
+              child: PostTagsPanel(post: post),
+            ),
+          ],
+        ),
+      ],
+    );
+  }
+
+  Future<void> _addToCollection(
+    BuildContext context,
+    WidgetRef ref,
+    Post post,
+  ) async {
+    final result = await ref.read(collectionServiceProvider).getCollections();
+    final collections =
+        result is Success<List<Collection>> ? result.data : <Collection>[];
+    if (!context.mounted) return;
+    await showAddToCollectionPicker(
+      context,
+      collections: collections,
+      onSelected: (collection) {
+        ref
+            .read(collectionServiceProvider)
+            .addPostToCollection(collection.id, post);
+      },
+      onCreate: () => showCollectionFormDialog(context, ref),
+    );
+  }
+
+  Future<void> _download(BuildContext context, Post post) async {
+    final filename = p.basename(Uri.parse(post.fileUrl).path);
+    final location = await getSaveLocation(suggestedName: filename);
+    if (location == null) return;
+    if (!context.mounted) return;
+    ScaffoldMessenger.of(context).showSnackBar(
+      const SnackBar(content: Text('Downloading...')),
+    );
+    await Dio().download(post.fileUrl, location.path);
+    if (!context.mounted) return;
+    ScaffoldMessenger.of(context).showSnackBar(
+      const SnackBar(content: Text('Download complete')),
+    );
+  }
+
+  void _openPost(BuildContext context, Post post) {
+    context.go('/post/${post.providerId}/${post.id}', extra: post);
+  }
+
+  void _close(BuildContext context) {
+    if (Navigator.of(context).canPop()) {
+      context.pop();
+      return;
+    }
+    context.go('/');
+  }
+}

lib/features/post/presentation/widgets/post_action_bar.dart

@@ -0,0 +1,54 @@
+import 'package:flutter/material.dart';
+
+class PostActionBar extends StatelessWidget {
+  const PostActionBar({
+    required this.onFavorite,
+    required this.onCollection,
+    required this.onOpen,
+    required this.onCopy,
+    this.onDownload,
+    super.key,
+  });
+
+  final VoidCallback onFavorite;
+  final VoidCallback onCollection;
+  final VoidCallback onOpen;
+  final VoidCallback onCopy;
+  final VoidCallback? onDownload;
+
+  @override
+  Widget build(BuildContext context) {
+    return Wrap(
+      spacing: 8,
+      runSpacing: 8,
+      children: [
+        FilledButton.icon(
+          onPressed: onFavorite,
+          icon: const Icon(Icons.favorite_rounded),
+          label: const Text('Favorite'),
+        ),
+        FilledButton.tonalIcon(
+          onPressed: onCollection,
+          icon: const Icon(Icons.add_rounded),
+          label: const Text('Collection'),
+        ),
+        IconButton.filledTonal(
+          tooltip: 'Open original',
+          onPressed: onOpen,
+          icon: const Icon(Icons.open_in_new_rounded),
+        ),
+        IconButton.filledTonal(
+          tooltip: 'Copy link',
+          onPressed: onCopy,
+          icon: const Icon(Icons.copy_rounded),
+        ),
+        if (onDownload != null)
+          IconButton.filledTonal(
+            tooltip: 'Download',
+            onPressed: onDownload,
+            icon: const Icon(Icons.download_rounded),
+          ),
+      ],
+    );
+  }
+}

lib/features/post/presentation/widgets/post_media_viewer.dart

@@ -0,0 +1,323 @@
+import 'dart:async';
+
+import 'package:cached_network_image/cached_network_image.dart';
+import 'package:flutter/material.dart';
+import 'package:media_kit/media_kit.dart';
+import 'package:media_kit_video/media_kit_video.dart';
+
+import '../../../../backend/backend.dart';
+
+class PostMediaViewer extends StatefulWidget {
+  const PostMediaViewer({required this.post, super.key});
+
+  final Post post;
+
+  @override
+  State<PostMediaViewer> createState() => _PostMediaViewerState();
+}
+
+class _PostMediaViewerState extends State<PostMediaViewer> {
+  Player? _player;
+  VideoController? _controller;
+  late List<String> _imageUrls;
+  int _imageIndex = 0;
+  bool _controlsVisible = true;
+  bool _coverVideo = false;
+  bool _muted = false;
+  Timer? _hideTimer;
+
+  @override
+  void initState() {
+    super.initState();
+    _imageUrls = _buildImageUrls(widget.post);
+    if (widget.post.fileType == 'video') {
+      MediaKit.ensureInitialized();
+      _player = Player();
+      _controller = VideoController(_player!);
+      _player!.open(Media(widget.post.fileUrl), play: false);
+      _scheduleControlsHide();
+    }
+  }
+
+  @override
+  void dispose() {
+    _hideTimer?.cancel();
+    _player?.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    if (_controller != null) {
+      return _VideoSurface(
+        player: _player!,
+        controller: _controller!,
+        aspectRatio: widget.post.width > 0 && widget.post.height > 0
+            ? widget.post.width / widget.post.height
+            : 16 / 9,
+        controlsVisible: _controlsVisible,
+        coverVideo: _coverVideo,
+        muted: _muted,
+        onInteract: _showControls,
+        onToggleFit: () {
+          setState(() => _coverVideo = !_coverVideo);
+          _showControls();
+        },
+        onToggleMute: () async {
+          final nextMuted = !_muted;
+          setState(() => _muted = nextMuted);
+          await _player!.setVolume(nextMuted ? 0 : 100);
+          _showControls();
+        },
+      );
+    }
+    final url = _imageUrls.isEmpty ? '' : _imageUrls[_imageIndex];
+    return InteractiveViewer(
+      child: CachedNetworkImage(
+        key: ValueKey(url),
+        imageUrl: url,
+        httpHeaders: _headersFor(widget.post),
+        fit: BoxFit.contain,
+        placeholder: (context, url) =>
+            const Center(child: CircularProgressIndicator()),
+        errorWidget: (context, url, error) {
+          if (_imageIndex < _imageUrls.length - 1) {
+            WidgetsBinding.instance.addPostFrameCallback((_) {
+              if (mounted) setState(() => _imageIndex++);
+            });
+            return const Center(child: CircularProgressIndicator());
+          }
+          return const Center(
+            child: Column(
+              mainAxisSize: MainAxisSize.min,
+              children: [
+                Icon(Icons.broken_image_rounded, size: 48),
+                SizedBox(height: 8),
+                Text('Could not load image'),
+              ],
+            ),
+          );
+        },
+      ),
+    );
+  }
+
+  List<String> _buildImageUrls(Post post) {
+    return {
+      post.sampleUrl,
+      post.fileUrl,
+      post.previewUrl,
+    }.where((url) => url.trim().isNotEmpty).toList();
+  }
+
+  Map<String, String> _headersFor(Post post) {
+    return {
+      'User-Agent': 'GelRuleApp/0.1 Flutter local booru browser',
+      if (post.providerName.toLowerCase().contains('gelbooru') ||
+          post.fileUrl.contains('gelbooru.com') ||
+          post.sampleUrl.contains('gelbooru.com') ||
+          post.previewUrl.contains('gelbooru.com'))
+        'Referer': 'https://gelbooru.com/',
+    };
+  }
+
+  void _showControls() {
+    if (!mounted) return;
+    setState(() => _controlsVisible = true);
+    _scheduleControlsHide();
+  }
+
+  void _scheduleControlsHide() {
+    _hideTimer?.cancel();
+    _hideTimer = Timer(const Duration(seconds: 3), () {
+      if (mounted) setState(() => _controlsVisible = false);
+    });
+  }
+}
+
+class _VideoSurface extends StatelessWidget {
+  const _VideoSurface({
+    required this.player,
+    required this.controller,
+    required this.aspectRatio,
+    required this.controlsVisible,
+    required this.coverVideo,
+    required this.muted,
+    required this.onInteract,
+    required this.onToggleFit,
+    required this.onToggleMute,
+  });
+
+  final Player player;
+  final VideoController controller;
+  final double aspectRatio;
+  final bool controlsVisible;
+  final bool coverVideo;
+  final bool muted;
+  final VoidCallback onInteract;
+  final VoidCallback onToggleFit;
+  final VoidCallback onToggleMute;
+
+  @override
+  Widget build(BuildContext context) {
+    return MouseRegion(
+      onHover: (_) => onInteract(),
+      child: GestureDetector(
+        onTap: onInteract,
+        child: ClipRRect(
+          borderRadius: BorderRadius.circular(10),
+          child: AspectRatio(
+            aspectRatio: aspectRatio.clamp(0.35, 2.4),
+            child: Stack(
+              fit: StackFit.expand,
+              children: [
+                ColoredBox(
+                  color: Colors.black,
+                  child: Video(
+                    controller: controller,
+                    fit: coverVideo ? BoxFit.cover : BoxFit.contain,
+                    controls: null,
+                  ),
+                ),
+                AnimatedOpacity(
+                  opacity: controlsVisible ? 1 : 0,
+                  duration: const Duration(milliseconds: 180),
+                  child: _VideoControls(
+                    player: player,
+                    muted: muted,
+                    coverVideo: coverVideo,
+                    onToggleFit: onToggleFit,
+                    onToggleMute: onToggleMute,
+                  ),
+                ),
+              ],
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+}
+
+class _VideoControls extends StatelessWidget {
+  const _VideoControls({
+    required this.player,
+    required this.muted,
+    required this.coverVideo,
+    required this.onToggleFit,
+    required this.onToggleMute,
+  });
+
+  final Player player;
+  final bool muted;
+  final bool coverVideo;
+  final VoidCallback onToggleFit;
+  final VoidCallback onToggleMute;
+
+  @override
+  Widget build(BuildContext context) {
+    return DecoratedBox(
+      decoration: BoxDecoration(
+        gradient: LinearGradient(
+          begin: Alignment.bottomCenter,
+          end: Alignment.topCenter,
+          colors: [
+            Colors.black.withValues(alpha: 0.7),
+            Colors.black.withValues(alpha: 0.18),
+            Colors.transparent,
+          ],
+        ),
+      ),
+      child: Align(
+        alignment: Alignment.bottomCenter,
+        child: Padding(
+          padding: const EdgeInsets.all(12),
+          child: StreamBuilder<bool>(
+            stream: player.stream.playing,
+            initialData: player.state.playing,
+            builder: (context, playingSnapshot) {
+              final playing = playingSnapshot.data ?? false;
+              return StreamBuilder<Duration>(
+                stream: player.stream.duration,
+                initialData: player.state.duration,
+                builder: (context, durationSnapshot) {
+                  final duration = durationSnapshot.data ?? Duration.zero;
+                  return StreamBuilder<Duration>(
+                    stream: player.stream.position,
+                    initialData: player.state.position,
+                    builder: (context, positionSnapshot) {
+                      final position = positionSnapshot.data ?? Duration.zero;
+                      final maxMs =
+                          duration.inMilliseconds.clamp(1, 1 << 31).toDouble();
+                      final valueMs = position.inMilliseconds
+                          .clamp(0, maxMs.toInt())
+                          .toDouble();
+                      return Column(
+                        mainAxisAlignment: MainAxisAlignment.end,
+                        children: [
+                          Slider(
+                            value: valueMs,
+                            max: maxMs,
+                            onChanged: (value) => player.seek(
+                              Duration(milliseconds: value.round()),
+                            ),
+                          ),
+                          Row(
+                            children: [
+                              IconButton.filledTonal(
+                                tooltip: playing ? 'Pause' : 'Play',
+                                onPressed: player.playOrPause,
+                                icon: Icon(
+                                  playing
+                                      ? Icons.pause_rounded
+                                      : Icons.play_arrow_rounded,
+                                ),
+                              ),
+                              const SizedBox(width: 8),
+                              Text(
+                                '${_format(position)} / ${_format(duration)}',
+                                style: const TextStyle(color: Colors.white),
+                              ),
+                              const Spacer(),
+                              IconButton.filledTonal(
+                                tooltip: muted ? 'Unmute' : 'Mute',
+                                onPressed: onToggleMute,
+                                icon: Icon(
+                                  muted
+                                      ? Icons.volume_off_rounded
+                                      : Icons.volume_up_rounded,
+                                ),
+                              ),
+                              const SizedBox(width: 6),
+                              IconButton.filledTonal(
+                                tooltip: coverVideo ? 'Fit' : 'Fill',
+                                onPressed: onToggleFit,
+                                icon: Icon(
+                                  coverVideo
+                                      ? Icons.fit_screen_rounded
+                                      : Icons.crop_free_rounded,
+                                ),
+                              ),
+                            ],
+                          ),
+                        ],
+                      );
+                    },
+                  );
+                },
+              );
+            },
+          ),
+        ),
+      ),
+    );
+  }
+
+  String _format(Duration duration) {
+    final minutes = duration.inMinutes.remainder(60).toString().padLeft(2, '0');
+    final seconds = duration.inSeconds.remainder(60).toString().padLeft(2, '0');
+    final hours = duration.inHours;
+    if (hours > 0) return '$hours:$minutes:$seconds';
+    return '$minutes:$seconds';
+  }
+}

lib/features/post/presentation/widgets/post_tags_panel.dart

@@ -0,0 +1,26 @@
+import 'package:flutter/material.dart';
+import 'package:go_router/go_router.dart';
+
+import '../../../../backend/backend.dart';
+import '../../../../shared/widgets/tag_chip.dart';
+
+class PostTagsPanel extends StatelessWidget {
+  const PostTagsPanel({required this.post, super.key});
+
+  final Post post;
+
+  @override
+  Widget build(BuildContext context) {
+    return Wrap(
+      spacing: 8,
+      runSpacing: 8,
+      children: [
+        for (final tag in post.tags.take(80))
+          TagChip(
+            tag: tag,
+            onTap: () => context.go('/?q=${Uri.encodeQueryComponent(tag)}'),
+          ),
+      ],
+    );
+  }
+}

lib/features/providers/presentation/provider_check_screen.dart

@@ -0,0 +1,65 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+import '../../../backend/backend.dart';
+import '../../../core/utils/result.dart';
+import '../../../shared/widgets/adaptive_scaffold.dart';
+import '../../../shared/widgets/error_view.dart';
+import 'providers_controller.dart';
+import 'widgets/provider_health_tile.dart';
+
+class ProviderCheckScreen extends ConsumerWidget {
+  const ProviderCheckScreen({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final providers = ref.watch(providersControllerProvider);
+    final health = ref.watch(providerHealthProvider);
+    return AdaptiveScaffold(
+      title: 'Provider Check',
+      actions: [
+        IconButton(
+          tooltip: 'Check all',
+          onPressed: () => _checkAll(ref),
+          icon: const Icon(Icons.playlist_add_check_rounded),
+        ),
+      ],
+      body: providers.when(
+        loading: () => const Center(child: CircularProgressIndicator()),
+        error: (error, _) => ErrorView(message: error.toString()),
+        data: (items) => ListView.builder(
+          padding: const EdgeInsets.all(16),
+          itemCount: items.length,
+          itemBuilder: (context, index) {
+            final item = items[index];
+            return ProviderHealthTile(
+              config: item,
+              health: health[item.id],
+              onCheck: () => _checkOne(ref, item.id),
+            );
+          },
+        ),
+      ),
+    );
+  }
+
+  Future<void> _checkAll(WidgetRef ref) async {
+    final result = await ref.read(providerCheckServiceProvider).checkAll();
+    if (result is Success<List<ProviderHealth>>) {
+      ref.read(providerHealthProvider.notifier).state = {
+        for (final item in result.data) item.providerId: item,
+      };
+    }
+  }
+
+  Future<void> _checkOne(WidgetRef ref, String providerId) async {
+    final result =
+        await ref.read(providerCheckServiceProvider).checkOne(providerId);
+    if (result is Success<ProviderHealth>) {
+      ref.read(providerHealthProvider.notifier).state = {
+        ...ref.read(providerHealthProvider),
+        providerId: result.data,
+      };
+    }
+  }
+}

lib/features/providers/presentation/provider_form_screen.dart

@@ -0,0 +1,195 @@
+import 'dart:convert';
+
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:go_router/go_router.dart';
+
+import '../../../backend/backend.dart';
+import 'providers_controller.dart';
+
+class ProviderFormScreen extends ConsumerStatefulWidget {
+  const ProviderFormScreen({this.initialConfig, super.key});
+
+  final ContentProviderConfig? initialConfig;
+
+  @override
+  ConsumerState<ProviderFormScreen> createState() => _ProviderFormScreenState();
+}
+
+class _ProviderFormScreenState extends ConsumerState<ProviderFormScreen> {
+  late final TextEditingController _name;
+  late final TextEditingController _baseUrl;
+  late final TextEditingController _priority;
+  late final TextEditingController _timeout;
+  late final TextEditingController _headers;
+  late final TextEditingController _apiKey;
+  late final TextEditingController _userId;
+  late final TextEditingController _login;
+  late String _apiType;
+  late bool _enabled;
+
+  @override
+  void initState() {
+    super.initState();
+    final config = widget.initialConfig;
+    _name = TextEditingController(text: config?.name);
+    _baseUrl = TextEditingController(text: config?.baseUrl);
+    _priority =
+        TextEditingController(text: (config?.priority ?? 10).toString());
+    _timeout =
+        TextEditingController(text: (config?.timeoutSeconds ?? 20).toString());
+    _headers = TextEditingController(
+      text: jsonEncode(_visibleHeaders(config?.customHeaders ?? const {})),
+    );
+    _apiKey =
+        TextEditingController(text: config?.customHeaders['query.api_key']);
+    _userId =
+        TextEditingController(text: config?.customHeaders['query.user_id']);
+    _login = TextEditingController(text: config?.customHeaders['query.login']);
+    _apiType = config?.apiType ?? 'gelbooru';
+    _enabled = config?.enabled ?? true;
+  }
+
+  @override
+  void dispose() {
+    _name.dispose();
+    _baseUrl.dispose();
+    _priority.dispose();
+    _timeout.dispose();
+    _headers.dispose();
+    _apiKey.dispose();
+    _userId.dispose();
+    _login.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+          title: Text(
+              widget.initialConfig == null ? 'New provider' : 'Edit provider')),
+      body: ListView(
+        padding: const EdgeInsets.all(16),
+        children: [
+          TextField(
+              controller: _name,
+              decoration: const InputDecoration(labelText: 'Name')),
+          const SizedBox(height: 12),
+          TextField(
+              controller: _baseUrl,
+              decoration: const InputDecoration(labelText: 'Base URL')),
+          const SizedBox(height: 12),
+          DropdownButtonFormField<String>(
+            initialValue: _apiType,
+            decoration: const InputDecoration(labelText: 'API type'),
+            items: const [
+              DropdownMenuItem(
+                  value: 'gelbooru', child: Text('gelbooru-compatible')),
+              DropdownMenuItem(
+                  value: 'rule34', child: Text('rule34-compatible')),
+              DropdownMenuItem(
+                  value: 'danbooru', child: Text('danbooru-compatible')),
+              DropdownMenuItem(value: 'custom', child: Text('custom')),
+            ],
+            onChanged: (value) =>
+                setState(() => _apiType = value ?? 'gelbooru'),
+          ),
+          const SizedBox(height: 12),
+          SwitchListTile(
+            value: _enabled,
+            title: const Text('Enabled'),
+            onChanged: (value) => setState(() => _enabled = value),
+          ),
+          TextField(
+            controller: _priority,
+            keyboardType: TextInputType.number,
+            decoration: const InputDecoration(labelText: 'Priority'),
+          ),
+          const SizedBox(height: 12),
+          TextField(
+            controller: _timeout,
+            keyboardType: TextInputType.number,
+            decoration: const InputDecoration(labelText: 'Timeout seconds'),
+          ),
+          const SizedBox(height: 12),
+          Text('Provider API credentials',
+              style: Theme.of(context).textTheme.titleMedium),
+          const SizedBox(height: 8),
+          TextField(
+            controller: _apiKey,
+            decoration: const InputDecoration(
+              labelText: 'API key',
+              helperText: 'Gelbooru: api_key, Danbooru: api_key',
+            ),
+          ),
+          const SizedBox(height: 12),
+          TextField(
+            controller: _userId,
+            decoration: const InputDecoration(
+              labelText: 'User ID',
+              helperText: 'Gelbooru-compatible APIs may require user_id',
+            ),
+          ),
+          const SizedBox(height: 12),
+          TextField(
+            controller: _login,
+            decoration: const InputDecoration(
+              labelText: 'Login',
+              helperText: 'Danbooru-compatible APIs may require login',
+            ),
+          ),
+          const SizedBox(height: 12),
+          TextField(
+            controller: _headers,
+            minLines: 3,
+            maxLines: 6,
+            decoration: const InputDecoration(labelText: 'Custom headers JSON'),
+          ),
+          const SizedBox(height: 20),
+          FilledButton.icon(
+            onPressed: _save,
+            icon: const Icon(Icons.save_rounded),
+            label: const Text('Save provider'),
+          ),
+        ],
+      ),
+    );
+  }
+
+  Future<void> _save() async {
+    final now = DateTime.now();
+    final id = widget.initialConfig?.id ??
+        _name.text.trim().toLowerCase().replaceAll(RegExp(r'[^a-z0-9]+'), '_');
+    final headersJson =
+        jsonDecode(_headers.text.trim().isEmpty ? '{}' : _headers.text);
+    final customHeaders = Map<String, String>.from(headersJson as Map);
+    void putQuery(String key, String value) {
+      final trimmed = value.trim();
+      if (trimmed.isNotEmpty) customHeaders['query.$key'] = trimmed;
+    }
+
+    putQuery('api_key', _apiKey.text);
+    putQuery('user_id', _userId.text);
+    putQuery('login', _login.text);
+    final config = ContentProviderConfig(
+      id: id,
+      name: _name.text.trim(),
+      baseUrl: _baseUrl.text.trim(),
+      apiType: _apiType,
+      enabled: _enabled,
+      priority: int.tryParse(_priority.text) ?? 10,
+      timeoutSeconds: int.tryParse(_timeout.text) ?? 20,
+      customHeaders: customHeaders,
+      createdAt: widget.initialConfig?.createdAt ?? now,
+      updatedAt: now,
+    );
+    await ref.read(providersControllerProvider.notifier).save(config);
+    if (mounted) context.go('/providers');
+  }
+
+  Map<String, String> _visibleHeaders(Map<String, String> headers) {
+    return Map<String, String>.from(headers)
+      ..removeWhere((key, _) => key.startsWith('query.'));
+  }
+}

lib/features/providers/presentation/providers_controller.dart

@@ -0,0 +1,40 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+import '../../../backend/backend.dart';
+import '../../../core/utils/result.dart';
+
+final providersControllerProvider =
+    AsyncNotifierProvider<ProvidersController, List<ContentProviderConfig>>(
+  ProvidersController.new,
+);
+
+class ProvidersController extends AsyncNotifier<List<ContentProviderConfig>> {
+  @override
+  Future<List<ContentProviderConfig>> build() => _load();
+
+  Future<void> toggle(String id, bool enabled) async {
+    await ref.read(providerManagerProvider).enableProvider(id, enabled);
+    state = AsyncData(await _load());
+  }
+
+  Future<void> save(ContentProviderConfig config) async {
+    await ref.read(providerManagerProvider).addCustomProvider(config);
+    state = AsyncData(await _load());
+  }
+
+  Future<void> delete(String id) async {
+    await ref.read(providerManagerProvider).deleteProvider(id);
+    state = AsyncData(await _load());
+  }
+
+  Future<List<ContentProviderConfig>> _load() async {
+    final result =
+        await ref.read(providerManagerProvider).loadConfigs(enabledOnly: false);
+    return result is Success<List<ContentProviderConfig>>
+        ? result.data
+        : const [];
+  }
+}
+
+final providerHealthProvider =
+    StateProvider<Map<String, ProviderHealth>>((ref) => {});

lib/features/providers/presentation/providers_screen.dart

@@ -0,0 +1,63 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:go_router/go_router.dart';
+
+import '../../../shared/widgets/adaptive_scaffold.dart';
+import '../../../shared/widgets/confirm_dialog.dart';
+import '../../../shared/widgets/error_view.dart';
+import 'providers_controller.dart';
+import 'widgets/provider_card.dart';
+
+class ProvidersScreen extends ConsumerWidget {
+  const ProvidersScreen({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final providers = ref.watch(providersControllerProvider);
+    return AdaptiveScaffold(
+      title: 'Providers',
+      actions: [
+        IconButton(
+          tooltip: 'Check providers',
+          onPressed: () => context.go('/providers/check'),
+          icon: const Icon(Icons.network_check_rounded),
+        ),
+        IconButton(
+          tooltip: 'Add provider',
+          onPressed: () => context.go('/providers/new'),
+          icon: const Icon(Icons.add_rounded),
+        ),
+      ],
+      body: providers.when(
+        loading: () => const Center(child: CircularProgressIndicator()),
+        error: (error, _) => ErrorView(message: error.toString()),
+        data: (items) => ListView.builder(
+          padding: const EdgeInsets.all(16),
+          itemCount: items.length,
+          itemBuilder: (context, index) {
+            final item = items[index];
+            return ProviderCard(
+              config: item,
+              onToggle: (enabled) => ref
+                  .read(providersControllerProvider.notifier)
+                  .toggle(item.id, enabled),
+              onEdit: () => context.go('/providers/new', extra: item),
+              onDelete: () async {
+                final ok = await showConfirmDialog(
+                  context,
+                  title: 'Delete provider',
+                  message: 'Remove ${item.name}?',
+                );
+                if (ok) {
+                  await ref
+                      .read(providersControllerProvider.notifier)
+                      .delete(item.id);
+                }
+              },
+            );
+          },
+        ),
+      ),
+    );
+  }
+}

lib/features/providers/presentation/widgets/provider_card.dart

@@ -0,0 +1,46 @@
+import 'package:flutter/material.dart';
+
+import '../../../../backend/backend.dart';
+
+class ProviderCard extends StatelessWidget {
+  const ProviderCard({
+    required this.config,
+    required this.onToggle,
+    required this.onEdit,
+    required this.onDelete,
+    super.key,
+  });
+
+  final ContentProviderConfig config;
+  final ValueChanged<bool> onToggle;
+  final VoidCallback onEdit;
+  final VoidCallback onDelete;
+
+  @override
+  Widget build(BuildContext context) {
+    return Card(
+      child: ListTile(
+        leading: Switch(value: config.enabled, onChanged: onToggle),
+        title: Text(config.name),
+        subtitle: Text(
+            '${config.apiType} · ${config.baseUrl}\nPriority ${config.priority}'),
+        isThreeLine: true,
+        trailing: Wrap(
+          spacing: 4,
+          children: [
+            IconButton(
+              tooltip: 'Edit',
+              onPressed: onEdit,
+              icon: const Icon(Icons.edit_rounded),
+            ),
+            IconButton(
+              tooltip: 'Delete',
+              onPressed: onDelete,
+              icon: const Icon(Icons.delete_rounded),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}

lib/features/providers/presentation/widgets/provider_health_tile.dart

@@ -0,0 +1,40 @@
+import 'package:flutter/material.dart';
+
+import '../../../../backend/backend.dart';
+import '../../../../shared/widgets/provider_status_badge.dart';
+
+class ProviderHealthTile extends StatelessWidget {
+  const ProviderHealthTile({
+    required this.config,
+    required this.health,
+    required this.onCheck,
+    super.key,
+  });
+
+  final ContentProviderConfig config;
+  final ProviderHealth? health;
+  final VoidCallback onCheck;
+
+  @override
+  Widget build(BuildContext context) {
+    return Card(
+      child: ListTile(
+        title: Text(config.name),
+        subtitle: Text(
+          [
+            if (health != null) 'Ping ${health!.pingMs} ms',
+            if (health?.lastCheckedAt != null)
+              'Checked ${health!.lastCheckedAt}',
+            if (health?.errorMessage != null) health!.errorMessage!,
+          ].join('\n'),
+        ),
+        leading: ProviderStatusBadge(health: health),
+        trailing: IconButton(
+          tooltip: 'Check',
+          onPressed: onCheck,
+          icon: const Icon(Icons.network_check_rounded),
+        ),
+      ),
+    );
+  }
+}

lib/features/search/presentation/search_controller.dart

@@ -0,0 +1,42 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+import '../../../backend/backend.dart';
+import '../../../core/utils/result.dart';
+import 'search_state.dart';
+
+final searchControllerProvider =
+    AsyncNotifierProvider<SearchController, SearchState>(SearchController.new);
+
+class SearchController extends AsyncNotifier<SearchState> {
+  @override
+  Future<SearchState> build() async {
+    final recent = await _recent();
+    return SearchState(recent: recent);
+  }
+
+  Future<void> updateQuery(String query) async {
+    final lastToken =
+        query.trim().isEmpty ? '' : query.trim().split(RegExp(r'\s+')).last;
+    final suggestionsResult =
+        await ref.read(searchServiceProvider).autocomplete(lastToken);
+    final suggestions = suggestionsResult is Success<List<String>>
+        ? suggestionsResult.data
+        : <String>[];
+    state = AsyncData(
+      (state.value ?? const SearchState()).copyWith(
+        query: query,
+        suggestions: suggestions,
+      ),
+    );
+  }
+
+  Future<void> clearHistory() async {
+    await ref.read(searchServiceProvider).clearHistory();
+    state = const AsyncData(SearchState());
+  }
+
+  Future<List<SearchHistory>> _recent() async {
+    final result = await ref.read(searchServiceProvider).recentSearches();
+    return result is Success<List<SearchHistory>> ? result.data : const [];
+  }
+}

lib/features/search/presentation/search_screen.dart

@@ -0,0 +1,73 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:go_router/go_router.dart';
+
+import '../../../shared/widgets/adaptive_scaffold.dart';
+import '../../../shared/widgets/app_search_bar.dart';
+import '../../../shared/widgets/error_view.dart';
+import 'search_controller.dart';
+import 'widgets/recent_searches.dart';
+import 'widgets/search_suggestions.dart';
+
+class SearchScreen extends ConsumerWidget {
+  const SearchScreen({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final state = ref.watch(searchControllerProvider);
+    return AdaptiveScaffold(
+      title: 'Search',
+      actions: [
+        IconButton(
+          tooltip: 'Clear history',
+          onPressed: () =>
+              ref.read(searchControllerProvider.notifier).clearHistory(),
+          icon: const Icon(Icons.delete_sweep_rounded),
+        ),
+      ],
+      body: state.when(
+        loading: () => const Center(child: CircularProgressIndicator()),
+        error: (error, _) => ErrorView(message: error.toString()),
+        data: (data) => ListView(
+          padding: const EdgeInsets.all(16),
+          children: [
+            AppSearchBar(
+              onSubmitted: (query) =>
+                  context.go('/?q=${Uri.encodeQueryComponent(query)}'),
+              onChanged: (query) => ref
+                  .read(searchControllerProvider.notifier)
+                  .updateQuery(query),
+            ),
+            const SizedBox(height: 16),
+            SearchSuggestions(
+              suggestions: data.suggestions,
+              onTap: (suggestion) {
+                final query = _applySuggestion(data.query, suggestion);
+                context.go('/?q=${Uri.encodeQueryComponent(query)}');
+              },
+            ),
+            const SizedBox(height: 24),
+            Text('Recent', style: Theme.of(context).textTheme.titleLarge),
+            const SizedBox(height: 8),
+            RecentSearches(
+              items: data.recent,
+              onTap: (query) =>
+                  context.go('/?q=${Uri.encodeQueryComponent(query)}'),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+
+  String _applySuggestion(String query, String suggestion) {
+    final tokens =
+        query.trim().isEmpty ? <String>[] : query.trim().split(RegExp(r'\s+'));
+    if (tokens.isEmpty) {
+      tokens.add(suggestion);
+    } else {
+      tokens[tokens.length - 1] = suggestion;
+    }
+    return tokens.toSet().join(' ');
+  }
+}

lib/features/search/presentation/search_state.dart

@@ -0,0 +1,25 @@
+import '../../../backend/backend.dart';
+
+class SearchState {
+  const SearchState({
+    this.recent = const [],
+    this.suggestions = const [],
+    this.query = '',
+  });
+
+  final List<SearchHistory> recent;
+  final List<String> suggestions;
+  final String query;
+
+  SearchState copyWith({
+    List<SearchHistory>? recent,
+    List<String>? suggestions,
+    String? query,
+  }) {
+    return SearchState(
+      recent: recent ?? this.recent,
+      suggestions: suggestions ?? this.suggestions,
+      query: query ?? this.query,
+    );
+  }
+}

lib/features/search/presentation/widgets/recent_searches.dart

@@ -0,0 +1,27 @@
+import 'package:flutter/material.dart';
+
+import '../../../../backend/backend.dart';
+
+class RecentSearches extends StatelessWidget {
+  const RecentSearches({required this.items, required this.onTap, super.key});
+
+  final List<SearchHistory> items;
+  final ValueChanged<String> onTap;
+
+  @override
+  Widget build(BuildContext context) {
+    if (items.isEmpty) return const Text('No recent searches');
+    return Column(
+      children: [
+        for (final item in items)
+          ListTile(
+            leading: const Icon(Icons.history_rounded),
+            title: Text(item.query),
+            subtitle:
+                Text('${item.tags.join(' ')} · ${item.resultCount} results'),
+            onTap: () => onTap(item.query),
+          ),
+      ],
+    );
+  }
+}