Three subcommands:
compile <pack_id> — compile a pack, verify checksum, print manifold stats
verify <pack_id> — checksum-only verification without full compilation
list — list all available packs with role and entry count
Checksum rule (AGENTS.md) is enforced by design: the CLI reads bytes from
disk via read_bytes() as the single source of truth, never from in-memory
strings. This makes the compiler an auditable D0 instrument — not just an
importable function.
Exit codes: 0 = success, 1 = checksum mismatch or pack not found.
