manpage cleanup: strip flags not taught anywhere
- audit every flag/keyword in each MANPAGE entry; remove those never used in level questions or scenarios
- trim flags from 47 commands (touch, less, find, wc, tar, ps, ssh, diff, docker, apt, dnf, hostname, etc.)
- drop
pacmanentry entirely — command never appears in any answer - delete 6 dead duplicate entries (hydra, airmon-ng, airodump-ng, aireplay-ng, aircrack-ng, openssl had earlier defs overridden by later)