🐛 fix(ci): prevent stale superpowers sync from restoring skills block

remove the stale superpowers list block from SKILLS.md so the document routes to the source list only.

clear assume-unchanged and skip-worktree flags in the sync workflow before refreshing the workspace, and add a regression test for that safeguard.

tests/test_superpowers_workflows.py

@@ -13,6 +13,11 @@ class SuperpowersWorkflowTests(unittest.TestCase):
         text = SYNC_WORKFLOW.read_text(encoding="utf-8")
         self.assertIn("workflow_dispatch:", text)
 
+    def test_sync_workflow_clears_stale_index_flags(self):
+        text = SYNC_WORKFLOW.read_text(encoding="utf-8")
+        self.assertIn("git update-index --no-assume-unchanged", text)
+        self.assertIn("--no-skip-worktree", text)
+
     def test_sync_workflow_runs_from_latest_main(self):
         text = SYNC_WORKFLOW.read_text(encoding="utf-8")
         self.assertIn('TARGET_BRANCH: "main"', text)