Reword the Pre-Commit Framework's "Stashes" Beside the Shared Stash Rule #2912

Finding

GOVERNANCE.md "Repository Boundaries and Write Safety" and the host-wide agent-safety block now say a task leaves the shared git stash list alone, because every worktree of a repository shares it.

Two unchanged lines describe the pre-commit framework as one that "stashes unstaged changes": a line in GOVERNANCE.md near the hook description, and catalog/snippets/pre-commit/README.md. Read beside the new rule, the verb can suggest that committing through the required hook writes to the shared stash list, which could lead a reader to skip hooks. The framework sets unstaged changes aside as a patch file in its own cache rather than in refs/stash, though this has not been confirmed against its source.

Suggested Fix

Confirm the framework's mechanism, then reword both lines to say it sets unstaged changes aside, so the verb no longer collides with the stash rule.

Found by the local review pass on the change that named the stash in the write-safety law.