2.2.0 (#13)

* Major system improvements: TCP state machine, SMP support, user address spaces, and more

Phase 1 - Userspace Improvements:
- Enhanced ELF loader for true userspace process execution
- Added user address space management (mm_struct, vm_area)
- Implemented vmm_map_user_page() and vmm_map_user_range()
- Created userspace media library header (user/lib/media.h)

Phase 2 - Network Stack:
- Implemented complete TCP state machine (SYN/SYN-ACK/ACK/FIN)
- Added tcp_send_packet() for building and sending TCP segments
- Added tcp_handle_segment() for processing incoming TCP
- Implemented ARP request/reply handling
- Added IP packet processing (ICMP, TCP, UDP dispatch)
- Proper connection tracking with tcp_find_connection()

Phase 3 - Hardware Improvements:
- Rewrote Intel HDA driver with proper DMA ring buffers
- Added 256KB ring buffer with 32 BDL entries
- Implemented intel_hda_stop() and intel_hda_is_playing()
- Added cache flush helpers for DMA coherency

SMP Support:
- Added spinlock implementation (spin_lock/spin_unlock)
- Implemented smp_processor_id(), smp_num_cpus()
- Added PSCI-based secondary CPU boot (smp_boot_secondary)
- Added per-CPU GIC initialization (gic_cpu_init)
- Added kernel-wide smp_lock()/smp_unlock()

Syscall Improvements:
- Implemented file descriptor table (MAX_FDS=256)
- sys_openat now properly opens files via VFS
- sys_read/sys_write now use FD table
- sys_close properly releases file descriptors
- sys_lseek implemented for file positioning
- sys_execve now loads ELF binaries

All changes maintain backwards compatibility with existing functionality.

* Add macOS-style Desktop Manager with icons, context menus, and graphics optimizations

Major Features:
- Desktop Manager: Shows files/folders from /Desktop directory with icon rendering
- Right-click context menu system with actions:
  - New Folder / New File creation
  - Open, Rename, Delete operations
  - Copy/Cut/Paste functionality
  - Sort by Name/Date/Type
  - Refresh desktop
- Icon types: Folder, File, Image, Audio, Text, App with visual representations
- Selection system with click and shift-click multi-select
- Double-click to open files/folders

Graphics Performance:
- Dirty rectangle tracking for partial screen updates
- Optimized compositor with fast memory copy
- Memory barriers for reliable frame updates
- Periodic full redraws (every 64 frames) for consistency

Infrastructure:
- VFS: Implemented vfs_unlink and vfs_rmdir functions
- RamFS: Added unlink/rmdir support for file deletion
- RamFS: Fixed ramfs_create_file to handle full paths correctly
- Created /Desktop directory with sample files on boot

Files Added:
- kernel/gui/desktop.c - Desktop manager implementation
- kernel/gui/desktop.h - Desktop manager header

Files Modified:
- kernel/gui/window.c - Integrated desktop manager
- kernel/fs/vfs.c - Added unlink/rmdir implementations
- kernel/fs/ramfs.c - Added unlink/rmdir operations, fixed path handling
- kernel/include/fs/vfs.h - Added ENOTEMPTY error code
- kernel/core/main.c - Create Desktop directory with sample files

* Fix desktop right-click context menu and add Windows-like features

Bug Fixes:
- Fixed right-click not showing context menu (was blocked by early return)
- Moved right-click handling before the left_click gate
- Fixed vfs_readdir callback argument order (was swapping ctx and filldir)

New Features:
- Windows-style context menu with comprehensive options:
  * File context menu: Open, Open with, Cut, Copy, Create shortcut, Delete, Rename, Properties
  * Desktop context menu: View, Sort by, Refresh, Paste, New Folder, New Text Document,
    New Shortcut, Open in Terminal, Display settings, Personalize
- Opening folders now opens File Manager with that folder's content
- Added gui_create_file_manager_path() to open File Manager at specific path
- Added gui_get_screen_width/Height() helper functions
- Context menu now stays within screen bounds

Technical:
- Centralized all extern declarations at top of desktop.c
- Fixed duplicate extern declaration errors
- Menu automatically repositions if too close to screen edge

* Update MicroPython and Nanolang vendor dependencies.

* feat: Update MicroPython core, ports, tests, and documentation, alongside Nanolang examples, modules, tests, and build artifacts.

* feat: Security overhaul, menu fixes, README update with new screenshots

- Add spinlock synchronization for kernel (ARM64/x86)
- Add media sandbox for fault isolation
- Add ASLR for process address randomization
- Fix menu dropdown click detection
- Fix window callback stale pointer bug
- Update README with new screenshots and Python/Nano support
- Add author attribution (JIJO JOHN)

* fix: Add CLONE_*/PF_THREAD flags and remove duplicate FD table code

- Add PF_THREAD, CLONE_VM, CLONE_FS, CLONE_FILES, CLONE_SIGHAND, CLONE_THREAD, CLONE_PARENT to sched.h
- Remove duplicate File Descriptor Table block in syscall.c (merge artifact)
- Fixes GitHub Actions build failure

* fix: Add sync and sandbox directories to Makefile.multiarch

- Add kernel/sync for spinlock support on x86_64
- Add kernel/sandbox for media sandbox support on x86_64
- Fixes undefined symbol errors for spin_lock_irqsave

* docs: Add Doom screenshot to README

* version updates , doom added etc minor

fix(ci): Add llvm package and make objdump optional

Fixes:
- Install llvm package in CI workflows for llvm-objdump
- Make objdump optional in Makefile.multiarch
- Gracefully skip sections dump if objdump not available

This fixes the CI build failure:
  /bin/sh: 1: llvm-objdump: not found
  make: *** [Makefile.multiarch:241] Error 127

Changes:
- .github/workflows/ci.yml: Add llvm to apt-get install
- .github/workflows/build-release.yml: Add llvm to apt-get install
- Makefile.multiarch: Check if objdump exists before using it