feat(linux): add build_linux_appimage.sh script for AppImage packaging

installer/build_linux_appimage.sh

@@ -0,0 +1,92 @@
+#!/usr/bin/env bash
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+ROOT_DIR="$(cd "${SCRIPT_DIR}/.." && pwd)"
+
+cd "${ROOT_DIR}"
+
+VERSION=$(grep 'version:' pubspec.yaml | head -n 1 | awk '{print $2}' | cut -d'+' -f1)
+if [ -z "$VERSION" ]; then
+  VERSION="3.5.5"
+fi
+
+echo "Building AppImage for Prisma v${VERSION}..."
+
+BUNDLE_DIR="${ROOT_DIR}/build/linux/x64/release/bundle"
+if [ ! -f "${BUNDLE_DIR}/gel_rule_app" ]; then
+  echo "Release bundle not found. Running 'flutter build linux --release'..."
+  flutter build linux --release
+fi
+
+APP_DIR="${ROOT_DIR}/build/AppDir"
+OUTPUT_DIR="${ROOT_DIR}/build"
+APPIMAGE_NAME="Prisma-v${VERSION}-linux-x86_64.AppImage"
+OUTPUT_APPIMAGE="${OUTPUT_DIR}/${APPIMAGE_NAME}"
+
+# Ensure appimagetool is available
+APPIMAGETOOL=""
+if command -v appimagetool >/dev/null 2>&1; then
+  APPIMAGETOOL="appimagetool"
+elif [ -f "${ROOT_DIR}/build/tools/appimagetool" ]; then
+  APPIMAGETOOL="${ROOT_DIR}/build/tools/appimagetool"
+else
+  echo "Downloading appimagetool..."
+  mkdir -p "${ROOT_DIR}/build/tools"
+  curl -fsSL https://github.com/AppImage/appimagetool/releases/download/continuous/appimagetool-x86_64.AppImage -o "${ROOT_DIR}/build/tools/appimagetool"
+  chmod +x "${ROOT_DIR}/build/tools/appimagetool"
+  APPIMAGETOOL="${ROOT_DIR}/build/tools/appimagetool"
+fi
+
+echo "Preparing AppDir at ${APP_DIR}..."
+rm -rf "${APP_DIR}"
+mkdir -p "${APP_DIR}"
+
+# Copy bundle contents
+cp -r "${BUNDLE_DIR}"/* "${APP_DIR}/"
+
+# AppRun script
+cat << 'EOF' > "${APP_DIR}/AppRun"
+#!/bin/sh
+HERE="$(dirname "$(readlink -f "${0}")")"
+export PATH="${HERE}/usr/bin:${PATH}"
+export LD_LIBRARY_PATH="${HERE}/lib:${HERE}/usr/lib:${LD_LIBRARY_PATH}"
+exec "${HERE}/gel_rule_app" "$@"
+EOF
+chmod +x "${APP_DIR}/AppRun"
+
+# Desktop file
+cat << 'EOF' > "${APP_DIR}/prisma.desktop"
+[Desktop Entry]
+Name=Prisma
+GenericName=Booru Client
+Comment=Prisma - Modern Booru & Art Client
+Exec=gel_rule_app %u
+Icon=prisma
+Terminal=false
+Type=Application
+Categories=Network;Graphics;
+StartupWMClass=com.example.gel_rule_app
+EOF
+
+mkdir -p "${APP_DIR}/usr/share/applications"
+cp "${APP_DIR}/prisma.desktop" "${APP_DIR}/usr/share/applications/prisma.desktop"
+
+# Icons
+ICON_SRC="${ROOT_DIR}/macos/Runner/Assets.xcassets/AppIcon.appiconset"
+if [ -d "${ICON_SRC}" ]; then
+  for size in 16 32 64 128 256 512 1024; do
+    if [ -f "${ICON_SRC}/app_icon_${size}.png" ]; then
+      mkdir -p "${APP_DIR}/usr/share/icons/hicolor/${size}x${size}/apps"
+      cp "${ICON_SRC}/app_icon_${size}.png" "${APP_DIR}/usr/share/icons/hicolor/${size}x${size}/apps/prisma.png"
+    fi
+  done
+  cp "${ICON_SRC}/app_icon_512.png" "${APP_DIR}/prisma.png"
+fi
+
+# Build AppImage
+echo "Generating AppImage with ${APPIMAGETOOL}..."
+ARCH=x86_64 "${APPIMAGETOOL}" -n "${APP_DIR}" "${OUTPUT_APPIMAGE}"
+
+echo "AppImage created successfully: ${OUTPUT_APPIMAGE}"
+ls -lh "${OUTPUT_APPIMAGE}"