fix(baremetal,net): fix bare-metal boot freezes and implement real internet stack

- Zero user PML4 and allocated page tables in VMM to prevent dirty RAM crash on real hardware
- Probe UART existence and add timeout to prevent infinite freeze on motherboards without COM1
- Clamp SMP AP boot to MAX_CPUS to prevent GDT/TSS corruption on multi-core CPUs
- Add kernel early framebuffer console (FbConsole) with 8x16 font for direct HDMI/DP screen output
- Configure Limine resolution and dynamic 4K draw buffers in gui_server to fix 1080p black screen
- Implement RFC 793 TCP pseudo-header checksum and full TCP 3-way handshake
- Implement DHCP client (UDP 67/68) and DNS client (UDP 53)
- Add dns, dhcp commands to shell and update web browser with live URL loading

limine.cfg

@@ -1,9 +1,11 @@
 # Limine Bootloader Configuration for opencoreC Microkernel
 timeout: 0
 default_entry: 1
+interface_resolution: 1280x800
 
 /opencoreC Microkernel (x86_64)
     protocol: limine
+    resolution: 1280x800x32
     kernel_path: boot():/boot/opencore_kernel.elf
     module_path: boot():/boot/init_server.elf
     module_path: boot():/boot/uart_driver.elf