Purpose
-------
Regression tests for :mod:`oct.mcp.safety` — ``SafetyGate`` HITL
enforcement.
Responsibilities
----------------
- Verify ``SafetyGate.check()`` HITL rules (rules 1-5).
- Verify oct_format double guard (apply + confirm).
- Verify non-destructive tools always proceed; destructive tools
require confirmation.
- Verify ``_format_confirmation_request`` sentinel and content.
- Verify T-08: no stateful replay surface (each call independent).
Diagnostics
-----------
Domain: MCP-TESTS
Levels:
L2 — test lifecycle
L3 — assertion details
L4 — deep tracing
Contracts
---------
- Tests are in-memory safety checks; no subprocess or filesystem writes.