feat: replace global issue lock with keyed persistent store (Closes #443)

Store per remote/org/repo/issue locks under GITEA_ISSUE_LOCK_DIR with
atomic writes and per-session binding. Integrate own-branch adoption for
lock recovery, update worktree-start and cleanup reconcile, and add tests
documenting the ban on manual global lock seeding.

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

tests/test_issue_lock_store.py

@@ -0,0 +1,181 @@
+"""Unit tests for keyed issue-lock storage (#443)."""
+import json
+import os
+import sys
+import tempfile
+import unittest
+from datetime import datetime, timedelta, timezone
+from pathlib import Path
+from unittest import mock
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
+
+import issue_lock_store as ils  # noqa: E402
+
+
+def _lease(expires_at: str) -> dict:
+    return {
+        "operation_type": ils.AUTHOR_ISSUE_WORK_LEASE,
+        "expires_at": expires_at,
+        "created_at": "2026-01-01T00:00:00Z",
+        "last_heartbeat_at": "2026-01-01T00:00:00Z",
+    }
+
+
+def _lock_record(**overrides) -> dict:
+    record = {
+        "issue_number": 420,
+        "branch_name": "feat/issue-420-server-code-parity",
+        "remote": "prgs",
+        "org": "Scaled-Tech-Consulting",
+        "repo": "Gitea-Tools",
+        "worktree_path": "/tmp/wt-420",
+        "work_lease": _lease("2999-01-01T00:00:00Z"),
+    }
+    record.update(overrides)
+    return record
+
+
+class TestIssueLockStore(unittest.TestCase):
+    def setUp(self):
+        self._dir = tempfile.TemporaryDirectory()
+        self.lock_dir = self._dir.name
+        self._env = mock.patch.dict(os.environ, {"GITEA_ISSUE_LOCK_DIR": self.lock_dir})
+        self._env.start()
+
+    def tearDown(self):
+        self._env.stop()
+        self._dir.cleanup()
+
+    def test_concurrent_repo_locks_do_not_overwrite(self):
+        lock_a = _lock_record(
+            issue_number=108,
+            branch_name="feat/issue-108-root-menu",
+            repo="mcp-control-plane",
+            worktree_path="/tmp/wt-108",
+        )
+        lock_b = _lock_record(
+            issue_number=420,
+            branch_name="feat/issue-420-server-code-parity",
+            repo="Gitea-Tools",
+            worktree_path="/tmp/wt-420",
+        )
+        path_a = ils.bind_session_lock(lock_a)
+        with mock.patch("os.getpid", return_value=9999):
+            path_b = ils.bind_session_lock(lock_b)
+
+        self.assertNotEqual(path_a, path_b)
+        self.assertTrue(os.path.exists(path_a))
+        self.assertTrue(os.path.exists(path_b))
+        stored_a = ils.read_lock_file(path_a)
+        stored_b = ils.read_lock_file(path_b)
+        self.assertEqual(stored_a["issue_number"], 108)
+        self.assertEqual(stored_b["issue_number"], 420)
+
+    def test_concurrent_issue_locks_same_repo_do_not_overwrite(self):
+        lock_a = _lock_record(issue_number=427, branch_name="feat/issue-427-a")
+        lock_b = _lock_record(issue_number=428, branch_name="feat/issue-428-b")
+        path_a = ils.bind_session_lock(lock_a)
+        with mock.patch("os.getpid", return_value=4242):
+            path_b = ils.bind_session_lock(lock_b)
+
+        self.assertNotEqual(path_a, path_b)
+        self.assertEqual(ils.read_lock_file(path_a)["issue_number"], 427)
+        self.assertEqual(ils.read_lock_file(path_b)["issue_number"], 428)
+
+    def test_foreign_live_lease_blocks_overwrite(self):
+        existing = _lock_record(
+            branch_name="feat/issue-420-other",
+            worktree_path="/tmp/other",
+            work_lease=_lease("2999-01-01T00:00:00Z"),
+        )
+        path = ils.lock_file_path(
+            remote="prgs",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            issue_number=420,
+        )
+        ils.save_lock_file(path, existing)
+
+        incoming = _lock_record(worktree_path="/tmp/mine")
+        block = ils.assess_foreign_lock_overwrite(existing, incoming)
+        self.assertIn("live foreign issue lock", block or "")
+
+    def test_expired_lease_allows_takeover_with_conflict_check(self):
+        existing = _lock_record(
+            branch_name="feat/issue-420-other",
+            worktree_path="/tmp/other",
+            work_lease=_lease("2000-01-01T00:00:00Z"),
+        )
+        incoming = _lock_record(worktree_path="/tmp/mine")
+        self.assertIsNone(ils.assess_foreign_lock_overwrite(existing, incoming))
+        block = ils.assess_same_issue_lease_conflict(
+            existing,
+            issue_number=420,
+            branch_name="feat/issue-420-server-code-parity",
+            worktree_path="/tmp/mine",
+        )
+        self.assertIn("Recovery review is required", block or "")
+
+    def test_same_owner_lease_conflict_allows_refresh(self):
+        worktree = "/tmp/wt-420"
+        existing = _lock_record(worktree_path=worktree)
+        block = ils.assess_same_issue_lease_conflict(
+            existing,
+            issue_number=420,
+            branch_name="feat/issue-420-server-code-parity",
+            worktree_path=worktree,
+        )
+        self.assertIsNone(block)
+
+    def test_find_lock_for_branch_after_restart(self):
+        record = _lock_record()
+        path = ils.lock_file_path(
+            remote="prgs",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            issue_number=420,
+        )
+        ils.save_lock_file(path, record)
+
+        with mock.patch("os.getpid", return_value=5555):
+            self.assertIsNone(ils.read_session_issue_lock())
+
+        found = ils.find_lock_for_branch(
+            remote="prgs",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            branch_name="feat/issue-420-server-code-parity",
+        )
+        self.assertEqual(found["issue_number"], 420)
+
+    def test_has_active_issue_lock_scans_keyed_store(self):
+        ils.bind_session_lock(_lock_record())
+        self.assertTrue(
+            ils.has_active_issue_lock("feat/issue-420-server-code-parity")
+        )
+        self.assertFalse(ils.has_active_issue_lock("feat/issue-999-other"))
+
+    def test_atomic_write_preserves_unrelated_lock(self):
+        path_a = ils.lock_file_path(
+            remote="prgs",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            issue_number=108,
+        )
+        ils.save_lock_file(path_a, _lock_record(issue_number=108, repo="mcp-control-plane"))
+        path_b = ils.lock_file_path(
+            remote="prgs",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            issue_number=420,
+        )
+        ils.save_lock_file(path_b, _lock_record())
+
+        self.assertTrue(os.path.exists(path_a))
+        self.assertTrue(os.path.exists(path_b))
+        self.assertEqual(ils.read_lock_file(path_a)["issue_number"], 108)
+
+
+if __name__ == "__main__":
+    unittest.main()