docs: add Global LLM Worktree Rule to operating rules (#272)

Require mutations only from branches/ worktrees after proving project
root, cwd, branch, stable main-checkout branch, and session worktree
path. Surface in portable skill, runbooks, wiki, operator guide, and
start-issue template.

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

docs/llm-workflow-runbooks.md

@@ -257,6 +257,34 @@ Gitea-Tools lease gates: `gitea_lock_issue` (fail-closed before author
 mutations), `status:in-progress`, and claim comments. Full portable wording:
 [`skills/llm-project-workflow/SKILL.md`](../skills/llm-project-workflow/SKILL.md).
 
+## Global LLM Worktree Rule
+
+The main project checkout is a stable control checkout. It must stay on the
+configured stable branch: `master`, `main`, or `dev`.
+
+All LLM task work must happen inside the project's `branches/` directory.
+
+Before any mutation, prove:
+
+1. current project root
+2. current working directory
+3. current branch
+4. stable branch for the main checkout
+5. session-owned worktree path under `branches/`
+
+If `cwd` is not inside `branches/`, stop. Do not edit, create, delete, format,
+test-write, commit, merge, rebase, checkout task branches, resolve conflicts,
+or run cleanup.
+
+There are no exceptions for small fixes, docs, tests, cleanup, PR review fixes,
+conflict resolution, or emergencies.
+
+The main checkout may only be used for read-only inspection, fetching,
+stable-branch update after merged PRs, creating `branches/` worktrees, or
+explicit control-checkout repair.
+
+Portable wording: [`skills/llm-project-workflow/SKILL.md`](../skills/llm-project-workflow/SKILL.md).
+
 ## Branch worktree isolation
 
 All LLM implementation and review work happens in an isolated branch worktree

docs/wiki/Operator-Guide.md

@@ -13,6 +13,7 @@ Handbook for LLM operators and human developers using the Gitea-Tools MCP server
 3. **One unit of work per session** — Implement one claimed issue *or* review/merge one PR; do not mix author and reviewer mutations in one session.
 4. **No self-review / no self-merge** — The authenticated Gitea user must not approve or merge a PR they authored.
 5. **Follow the gates** — Prompts express intent; MCP tools enforce safety. Never bypass gates via prompt instructions.
+6. **Global LLM Worktree Rule** — Main checkout stays on `master`/`main`/`dev`; all mutations happen under `branches/`. Prove project root, `cwd`, branch, stable main-checkout branch, and session worktree path before editing. No exceptions.
 
 ## Supported Gitea instances
 

docs/wiki/Workflow.md

@@ -17,6 +17,9 @@
 0. Work Selection Rule — verify a work lease before any mutations (open PRs,
    issue-linked PRs, branches, worktrees, dirty worktrees, active leases/
    handoffs, merged-PR completion). Stop if another session owns the lease.
+0b. Global LLM Worktree Rule — main checkout on `master`/`main`/`dev` only;
+   mutate only from a `branches/` worktree after proving root, cwd, branch,
+   stable main-checkout branch, and session worktree path (no exceptions).
 1. `gitea_resolve_task_capability` for the author task.
 2. `gitea_lock_issue` before implementation mutations.
 3. Claim with `gitea_mark_issue` / `status:in-progress` label.

gitea_mcp_server.py

@@ -3473,6 +3473,16 @@ _GUIDE_RULES = {
         "'work already claimed'). Never create a parallel branch/PR unless "
         "the old branch is proven abandoned and takeover is recorded. "
         "gitea_lock_issue is the fail-closed author lease gate."),
+    "global_worktree": (
+        "Main checkout is a stable control checkout on master/main/dev only. "
+        "All LLM task work happens under branches/. Before any mutation, prove "
+        "project root, cwd, branch, main-checkout stable branch, and "
+        "session-owned branches/ worktree path. If cwd is not under "
+        "branches/, stop — no edit/create/delete/format/test-write/commit/"
+        "merge/rebase/checkout/cleanup, with no exceptions (docs, tests, "
+        "small fixes, review fixes, conflicts, emergencies). Main checkout: "
+        "read-only inspect, fetch, create worktrees, post-merge stable "
+        "update, explicit repair only."),
 }
 
 _COMMON_WORKFLOWS = [
@@ -3481,6 +3491,9 @@ _COMMON_WORKFLOWS = [
     "work selection: acquire or verify a work lease before any issue/PR work "
     "(open PRs, linked PRs, branches, worktrees, dirty worktrees, leases, "
     "merged completion); stop if another session owns the lease.",
+    "global worktree: main checkout on master/main/dev only; mutate only "
+    "from a branches/ worktree after proving root, cwd, branch, stable "
+    "main-checkout branch, and session worktree path.",
     "issue authoring: verify identity, create/claim the issue, keep scope "
     "explicit (remote/org/repo).",
     "implementation: claim issue, branch from fresh master, implement only "

skills/llm-project-workflow/SKILL.md

@@ -89,10 +89,37 @@ mutations; `status:in-progress` and claim comments are supporting lease signals.
 Use `review_proofs.classify_issue_for_selection` when reporting fresh issue
 selection (#188).
 
+## Global LLM Worktree Rule
+
+The main project checkout is a stable control checkout. It must stay on the
+configured stable branch: `master`, `main`, or `dev`.
+
+All LLM task work must happen inside the project's `branches/` directory.
+
+Before any mutation, prove:
+
+1. current project root
+2. current working directory
+3. current branch
+4. stable branch for the main checkout
+5. session-owned worktree path under `branches/`
+
+If `cwd` is not inside `branches/`, stop. Do not edit, create, delete, format,
+test-write, commit, merge, rebase, checkout task branches, resolve conflicts,
+or run cleanup.
+
+There are no exceptions for small fixes, docs, tests, cleanup, PR review fixes,
+conflict resolution, or emergencies.
+
+The main checkout may only be used for read-only inspection, fetching,
+stable-branch update after merged PRs, creating `branches/` worktrees, or
+explicit control-checkout repair.
+
 ## B. Isolated worktree rule
 
-**Never implement or review in the main checkout.** The main checkout is for
-orchestration and status only (issue creation, `git status`, creating worktrees).
+**Never implement or review in the main checkout** (Global LLM Worktree Rule).
+The main checkout is for orchestration and status only (issue creation,
+`git status`, creating worktrees) and must remain on the stable branch.
 
 - Each issue gets its own branch worktree under an ignored `branches/` directory.
 - Review work uses a **separate** review worktree, never the author's folder.
@@ -180,7 +207,10 @@ Worktree folder = branch with `/` replaced by `-`
 
 0. Acquire or verify a work lease (Work Selection Rule) — complete all seven
    checks before any claim, branch, or PR work.
-1. Verify the orchestration checkout (right repo, clean tree).
+0b. Global LLM Worktree Rule — prove project root, `cwd`, branch, main-checkout
+    stable branch, and session-owned `branches/` worktree path. If `cwd` is not
+    under `branches/`, stop before any mutation (no exceptions).
+1. Verify the orchestration checkout (right repo, clean tree, on stable branch).
 2. Fetch/prune: `git fetch <remote> --prune`.
 3. Confirm local `master` equals remote `master` (`git rev-list --left-right --count <remote>/master...master` → `0	0`).
 4. Create/claim the issue (§A).

skills/llm-project-workflow/templates/start-issue.md

@@ -22,6 +22,12 @@ Steps:
    as lease owner, review the existing PR, hand off, request takeover after
    expiry, or report "work already claimed"). Never open a parallel branch/PR
    unless the old branch is proven abandoned and takeover is recorded.
+0b. Global LLM Worktree Rule — before any mutation, prove and state: project
+   root; cwd; current branch; stable branch for the main checkout (master/main/dev);
+   session-owned worktree path under branches/. If cwd is not inside branches/,
+   STOP (no exceptions — not for docs, tests, small fixes, review fixes, conflicts,
+   or cleanup). Main checkout is control-only: read-only inspect, fetch, create
+   worktrees, stable-branch update after merge, explicit repair.
 1. Identity Checklist: Before claiming work, verify and state:
    - Required identity/profile for this task: author (allowed to push branches / create PRs)
    - Current authenticated identity (from whoami): <username>

tests/test_operator_guide.py

@@ -133,7 +133,7 @@ class TestControlPlaneGuide(GuideTestBase):
         for key in ("hard_stops", "fail_closed", "head_sha_pinning",
                     "merge_confirmation", "redaction", "separation",
                     "profile_switching", "identity_verification",
-                    "work_selection"):
+                    "work_selection", "global_worktree"):
             self.assertIn(key, rules)
         self.assertIn("MERGE PR", json.dumps(rules["merge_confirmation"]))
         self.assertTrue(rules["hard_stops"])

tests/test_review_proofs.py

@@ -1053,6 +1053,8 @@ class TestControllerHandoff(unittest.TestCase):
         self.assertIn("issue #182", skill)
         self.assertIn("## Work Selection Rule for LLMs", skill)
         self.assertIn("work already claimed", skill)
+        self.assertIn("## Global LLM Worktree Rule", skill)
+        self.assertIn("branches/", skill)
 
     def test_handoff_rejects_none_workspace_mutations_when_local_edits_exist(self):
         # 1. Workspace mutations: none is rejected when local_edits is True