Diagnostic verbs (help, version, status, sandbox, doctor, state) now
reject unrecognized suffix arguments at parse time instead of silently
falling through to Prompt dispatch.
Fixes: claw doctor --json (and similar) no longer accepts --json silently
and attempts to send it to the LLM as a prompt. Now properly emits:
'unrecognized argument `--json` for subcommand `doctor`'
Joined parser-level trust gap quintet #108 + #117 + #119 + #122 + #127.
Prevents token burn on rejected arguments.
Verified: cargo build --workspace passes, claw doctor --json errors cleanly.
Refs: #127, ROADMAP
a3270db602