uid: add utmp syscalls and integrate with login

uid: add utmp syscalls and integrate with login

Implement UID Infrastructure: integração utmp/wtmp (completed).

Added syscalls for utmp management:
- SYSCALL_UTMP_LOGIN (145): register login session
- SYSCALL_UTMP_LOGOUT (146): register logout
- SYSCALL_UTMP_DEAD (147): register process death

Updated kernel syscall.c to handle utmp syscalls.
Updated kernel include/syscall.h with new syscall numbers.
Updated userspace include/syscall.h with new syscall numbers.
Updated userspace include/utmp.h with utmp_login/logout/dead declarations.
Updated userspace src/utmp.c with syscall wrappers.
Updated login command to call utmp_login() with TTY name and hostname.

Test: make test-battery PASS (157/157)