feat(reviewer): fail closed on dirty worktrees and forbidden git cleanup (#233)

Add reviewer_worktree proofs that block stash/reset/checkout -- cleanup of
unrelated local files, require scratch worktree reporting when the main tree
is dirty outside PR scope, and integrate the gate into final report grading
and Controller Handoff review fields.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

skills/llm-project-workflow/templates/review-pr.md

@@ -20,6 +20,15 @@ Repo name disambiguation (Gitea-Tools blind review hardening):
 
 Rules (llm-project-workflow):
 - Review in a SEPARATE detached review worktree, never the author's folder.
+- Worktree safety (#233): before checkout, diff, validation, review, or merge,
+  report the starting worktree path and whether it was dirty. If unrelated
+  tracked files exist outside the PR scope, STOP or run
+  `scripts/worktree-review <pr-head-branch>` and validate in the scratch path.
+  NEVER run `git stash`, `git stash pop/drop`, `git checkout --`, `git reset`,
+  or `git clean` to manage another session's dirty files.
+- Final report must state: Worktree path, Worktree dirty (yes/no),
+  Scratch worktree used (yes/no + path if yes), and confirm no unrelated local
+  files were modified, stashed, reset, or dropped.
 - You must NOT be the PR author. If the authenticated user == PR author, stop.
   A different LLM-Agent-SHA does NOT make you a different actor — only a
   different authenticated Gitea user does (docs/llm-agent-sha.md).