- Added Linux-compatible file metadata syscalls (stat, lstat, fstat, newfstatat)
- Implemented access control checks with faccessat and related flag definitions
- Added file persistence operations (fsync, fdatasync, truncate, ftruncate)
- Integrated clock syscalls (gettimeofday, clock_gettime, clock_getres)
- Added process identity queries (getpid, getppid, gettid, getuid, getgid)
- Changed exit mechanism from exit(60) to exit_group(231) for consistency
- Updated crt0.S with Linux x86-64 exit_group ABI compatibility
- Extended fcntl.h with AT_SYMLINK_NOFOLLOW and AT_EACCESS constants
- Added complete syscalls implementation in user/libc.c and runtime/posix.c
- Implemented kernel-side syscall handlers in process.c with proper validation
- Added systest utility to verify file metadata, persistence and identity calls
- Updated Makefile dependencies to track user header changes
- Enhanced README documentation for new
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