Teach land-stack when babysit jobs may resolve automated review threads.

product/skills/land-stack/SKILL.md

@@ -109,8 +109,16 @@ guard before any write (label, thread-resolve, queue, merge).
 - Do not bypass the guard by hand-adding a bypass label or merging directly to
   skip a broken check — if the queue is unhealthy, that's a different, riskier
   operation that needs its own explicit authorization, not this skill.
-- Do not resolve review threads to unblock a merge unless the user has decided
-  to defer those findings; record the deferral on the PR.
+- Do not resolve review threads to unblock a merge by default. Decision tree:
+  - **Automated review thread under an explicit babysit-until-merged job**
+    (for example CodeRabbit): after the current head addresses the thread
+    (or the thread is outdated), resolve it yourself via the GitHub
+    review-thread API. Do not bounce that to the user.
+  - **Deferral required for human reviewer threads:** resolve only when the
+    user has decided to defer those findings; record the deferral on the PR.
+    This rule alone never authorizes resolving a human thread.
+  - **Otherwise leave the thread open:** when there is no babysit-until-merged
+    job, or the head does not address the thread, leave it open.
 - Do not act on a PR whose head SHA is not in your local clone.
 
 ## Prove state before reporting it

product/skills/land-stack/tests/test_review_thread_decision_tree.py

@@ -0,0 +1,43 @@
+#!/usr/bin/env python3
+from __future__ import annotations
+
+import unittest
+from pathlib import Path
+
+SKILL = (Path(__file__).resolve().parents[1] / "SKILL.md").read_text(encoding="utf-8")
+
+
+class TestReviewThreadDecisionTree(unittest.TestCase):
+    def test_do_not_defaults_to_decision_tree(self):
+        self.assertIn(
+            "Do not resolve review threads to unblock a merge by default. Decision tree:",
+            SKILL,
+        )
+
+    def test_babysit_bot_thread_resolves_after_head_addresses(self):
+        start = SKILL.index(
+            "**Automated review thread under an explicit babysit-until-merged job**"
+        )
+        end = SKILL.index("**Deferral required for human reviewer threads:**")
+        bot = SKILL[start:end]
+        self.assertIn("current head addresses the thread", bot)
+        self.assertIn("or the thread is outdated", bot)
+        self.assertIn("Do not bounce that to the user", bot)
+
+    def test_human_thread_needs_recorded_deferral(self):
+        start = SKILL.index("**Deferral required for human reviewer threads:**")
+        end = SKILL.index("**Otherwise leave the thread open:**")
+        human = SKILL[start:end]
+        self.assertIn("record the deferral on the PR", human)
+        self.assertIn("This rule alone never", human)
+        self.assertIn("authorizes resolving a human thread", human)
+
+    def test_no_babysit_leaves_thread_open(self):
+        start = SKILL.index("**Otherwise leave the thread open:**")
+        otherwise = SKILL[start : start + 200]
+        self.assertIn("no babysit-until-merged", otherwise)
+        self.assertIn("leave it open", otherwise)
+
+
+if __name__ == "__main__":
+    unittest.main()