feat: Phase 2 — getrusage syscall, FIONREAD ioctl, libgen.h, misc ulibc

feat: Phase 2 — getrusage syscall, FIONREAD ioctl, libgen.h, misc ulibc

Kernel:
- Add SYSCALL_GETRUSAGE (137) returning process utime/stime as struct rusage
- Add FIONREAD (0x541B) ioctl to TTY (returns canon_buf available bytes)
- Add FIONREAD (0x541B) ioctl to pipe (returns pipe buffer count)

ulibc:
- sys/resource.h: Add RUSAGE_SELF/CHILDREN, struct rusage, getrusage()
- resource.c: Add getrusage() syscall wrapper
- libgen.h + libgen.c: basename() and dirname() implementations
- misc.c: gethostname() (returns 'adros'), ttyname(), pipe2() wrapper
- syscall.h: Add SYS_GETRUSAGE (137)

Tests: 101/101 smoke, 64/64 host utils, cppcheck clean