admin-bypass-sweep (1b) Step 5a calls the rebase probe

product/skills/admin-bypass-sweep/SKILL.md

@@ -193,32 +193,27 @@ human:
 
 These are mechanically distinguishable, and only the first one is the
 "real conflict" Step 5 means. Before recording a `CONFLICTING` PR as
-blocked, check which case it is, in a disposable worktree outside the
-human's main checkout — never touch their primary working tree's branch or
-uncommitted state to do this:
+blocked, run the rebase probe outside the human's main checkout — never
+touch their primary working tree's branch or uncommitted state to do this:
 
 ```bash
 git fetch origin master
-git worktree add /tmp/<scratch-dir>/pr-<n> origin/<pr-head-branch>
-cd /tmp/<scratch-dir>/pr-<n>
-git checkout -b fix/pr-<n>-rebase
-git rebase origin/master
+scripts/probe_branch_rebase.sh origin/<pr-head-branch> origin/master
 ```
 
-- **Rebase applies clean** (no conflict markers, `git status` clean) — this
-  was stale mergeability, not a real conflict. Force-push the rebased
-  branch back to the PR's head with `--force-with-lease` pinned to the
-  known old SHA, wait for GitHub to recompute (`sleep 5`), confirm
-  `mergeable` now reads `MERGEABLE`, then continue this PR (and its
-  children) through Step 4 as normal.
-- **Rebase stops with conflict markers** — this is Step 5's real-conflict
-  case. Run `git rebase --abort`, remove the scratch worktree, and follow
-  Step 5 as written: stop the chain, record as blocked, move on. Do not
-  attempt to resolve the markers by picking a side — that part of Step 5
-  still applies.
-
-Remove the scratch worktree (`git worktree remove --force`) once the PR's
-fate — merged or genuinely blocked — is decided.
+- **Exit 0, `OK`** — the PR rebases cleanly onto current master, so this was
+  stale mergeability rather than Step 5's real-conflict case. Wait for
+  GitHub to recompute (`sleep 5`), confirm `mergeable` now reads
+  `MERGEABLE`, then continue this PR (and its children) through Step 4 as
+  normal.
+- **Exit 1, `FAIL`** — the probe ran and found a real content conflict.
+  Follow Step 5 as written: stop the chain, record as blocked, and move on.
+  Do not attempt to resolve the markers by picking a side — that part of
+  Step 5 still applies.
+- **Exit 3, `UNCHECKED`** — the probe could not run, so nothing is proven.
+  Do not treat this as stale mergeability and do not treat it as Step 5's
+  real-conflict case; report the unchecked PR separately for manual retry
+  or setup repair.
 
 ## Step 6: Prove the final state
 

product/skills/admin-bypass-sweep/tests/fires_step5a_names_probe.md

@@ -0,0 +1,4 @@
+Fixture assertion: the Step 5a passage in
+`product/skills/admin-bypass-sweep/SKILL.md` must name
+`scripts/probe_branch_rebase.sh`, must name all three probe outcomes
+`OK`, `FAIL`, and `UNCHECKED`, and must not contain `rm -rf`.

product/skills/admin-bypass-sweep/tests/test_step5a_probe_passage.py

@@ -0,0 +1,38 @@
+#!/usr/bin/env python3
+from __future__ import annotations
+
+import re
+import unittest
+from pathlib import Path
+
+SKILL_DIR = Path(__file__).resolve().parents[1]
+SKILL = (SKILL_DIR / "SKILL.md").read_text(encoding="utf-8")
+FIXTURE = (SKILL_DIR / "tests" / "fires_step5a_names_probe.md").read_text(encoding="utf-8")
+
+
+def step5a_passage() -> str:
+    match = re.search(r"## Step 5a:.*?(?=\n## Step 6:)", SKILL, re.S)
+    if not match:
+        raise AssertionError("Step 5a passage not found")
+    return match.group(0)
+
+
+class TestStep5aProbePassage(unittest.TestCase):
+    def test_fixture_names_the_assertions(self):
+        self.assertIn("scripts/probe_branch_rebase.sh", FIXTURE)
+        for outcome in ("OK", "FAIL", "UNCHECKED"):
+            self.assertIn(outcome, FIXTURE)
+        self.assertIn("rm -rf", FIXTURE)
+
+    def test_step5a_names_probe_and_all_three_outcomes(self):
+        passage = step5a_passage()
+        self.assertIn("scripts/probe_branch_rebase.sh", passage)
+        for outcome in ("OK", "FAIL", "UNCHECKED"):
+            self.assertRegex(passage, rf"`{outcome}`")
+
+    def test_step5a_no_longer_contains_improvised_removal(self):
+        self.assertNotIn("rm -rf", step5a_passage())
+
+
+if __name__ == "__main__":
+    unittest.main()