#408 Prove parity cell: gitignored-delete gate (AN-1) on Codex

[Anonymous]

Originally created by: fu351

The parity matrix shows "Deleting unrecoverable gitignored data is gated" (AN-1) proven on Claude Code and the MCP proxy, but ◻ (not yet proven) on Codex. The guarantee: rm -rf of a gitignored, uncommitted directory (the classic "delete .env / local data" incident) escalates instead of sailing through as an ordinary delete.

What to do

1. Read the siblings: the gitignored-delete-gate test in tests/unit/test_hosthook_claude_pre.py (line ~121) proves the cell on Claude Code, and tests/unit/test_hosthook_codex.py already drives evaluate_pre with captured-shape Codex payloads for two other cells — combine the two and you have the whole test.
2. Write the Codex equivalent: a Codex Bash payload deleting a gitignored path, assert the escalation.
3. Mark it:
   python @pytest.mark.guarantee("gitignored-delete-gate", host="codex")
4. Mutation-check it (the bar for a ✅): temporarily disable the AN-1 rule, confirm your test goes red, revert. Note "mutation-checked" in the PR.
5. Regenerate the matrix: python -m tools.parity.generate_parity (CI's --check fails if you skip this).

The cell flips to ✅ automatically once the marked test is collected. Small, self-contained, and it proves a real Codex guarantee that today rests on "same spine, should hold."