The tool-contract guard cannot see a submodule pin rollback #2496

scripts/verify-moltbot-tool-contract.js asserts the _external/clawdbot pin is contained in the declared branch. That is true of every commit the branch ever had — and a rollback is by definition to a commit the branch already had — so containment can never catch one.

Measured on main 9ac61bdef, through the suite's own injected-exec seam: a pin that is a strict ancestor of the merge base's pin returns contained. #1089's exact shape passes the guard.

#1089 was caught because ux-lead read the diff by hand.

How the bad pin arrives is why the check must not key on intent: git add -A in a checkout whose submodule sits at an older commit stages that stale pointer as if it were an edit. The author types no submodule command, so a guard keyed on a title or a label misses the entire population — the regression happens precisely in PRs that believe they have nothing to do with the submodule.

Prior art: #1090 implemented the direction check in August and was re-reviewed clean, then never merged; it is two months behind main. Its own "Not verified" section names two gaps — the forward-bump cell was argued rather than exercised, and there was no unit test. A suite with an injected exec now exists (backend/__tests__/unit/scripts/moltbotToolContract.test.js), so both can be closed.

Row TASK-367 (SRE PR triage 2026-10-23).