feat(gui): Enable direct boot to GUI Desktop with emergency kernel TTY fallback

- Integrate Bochs/QEMU VBE physical LFB mapping directly to hardware video memory (0xFD000000)
- Update kernel boot sequence to directly boot into GUI Desktop by default
- Fall back to Emergency Kernel TTY Mode upon GUI exit (Esc key / Exit menu item)
- Support 'nogui', 'text', 'emergency', and 'single' boot arguments to boot directly into text mode
- Remove frame limits so GUI runs persistently

gui/gui_desktop.c

@@ -236,12 +236,6 @@ int gui_desktop_run(void) {
 
         // 4. Present Framebuffer to Display
         gui_gfx_present();
-
-        frame_limit++;
-        if (frame_limit > 500) {
-            // Safety break in non-interactive batch test
-            break;
-        }
     }
 
     printk(KERN_INFO "GUI: Desktop session ended, restored TTY console\n");