Purpose
-------
FS-539 / FS-501 (stub) — ``oct audit`` reads ``oc_status.json`` and
reports the project's Option C compliance stage.
This is the minimal landing surface that ``CLAUDE.md``'s compliance
probe and CI scripts consume. The full audit suite (schema drift,
scaffold age, doc/version mismatch, MCP readiness) lands in Phase 6.
Exit codes
----------
0 — compliant
1 — migrating
2 — bootstrap
3 — no oc_status.json found (unmigrated project)
Diagnostics
-----------
Domain: AUDIT
Levels:
L2 — lifecycle
Contracts
---------
- Read-only against the project tree; never writes.
- Exit code is derived from ``oc_status.json`` ``stage`` (or 3 when absent).
Dependencies
------------
- oct.core.diagnostics (_dbg structured logger)
- oct.core.option_c_dir (load_oc_status, option_c_dir)
- oct.core.project_root (project root detection)
- click (CLI framework)