feat: first-class control-plane lease lifecycle (Closes #601)

Make active leases queryable workflow state with canonical adopt, release,
expire/reclaim, and abandon operations on the #613 control-plane DB substrate.

- lease_lifecycle.py: policy, proof gates, safe_next_action vocabulary
- control_plane_db: schema v3 provenance columns + list/inspect/adopt/abandon
- MCP tools: gitea_*_workflow_lease(s) for list/inspect/adopt/release/expire/abandon/reclaim
- issue_lock_store: sanctioned reclaim of expired author locks (dead pid / missing wt)
- Tests cover lifecycle, foreign steal refusal, allocator compatibility, merger handoff

tests/test_issue_lock_store.py

@@ -103,20 +103,40 @@ class TestIssueLockStore(unittest.TestCase):
         self.assertIn("live foreign issue lock", block or "")
 
     def test_expired_lease_allows_takeover_with_conflict_check(self):
+        # #601: expired + dead pid / missing worktree → sanctioned reclaim (no block).
         existing = _lock_record(
             branch_name="feat/issue-420-other",
-            worktree_path="/tmp/other",
+            worktree_path="/tmp/other-does-not-exist-420",
+            session_pid=1,
             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",
+        with mock.patch.object(ils, "is_process_alive", return_value=False):
+            block = ils.assess_same_issue_lease_conflict(
+                existing,
+                issue_number=420,
+                branch_name="feat/issue-420-server-code-parity",
+                worktree_path="/tmp/mine",
+            )
+        self.assertIsNone(block)
+
+        # Expired but still-live owner pid AND present worktree → fail closed.
+        present_wt = self.lock_dir  # exists
+        sticky = _lock_record(
+            branch_name="feat/issue-420-other",
+            worktree_path=present_wt,
+            session_pid=os.getpid(),
+            work_lease=_lease("2000-01-01T00:00:00Z"),
         )
-        self.assertIn("Recovery review is required", block or "")
+        with mock.patch.object(ils, "is_process_alive", return_value=True):
+            blocked = ils.assess_same_issue_lease_conflict(
+                sticky,
+                issue_number=420,
+                branch_name="feat/issue-420-server-code-parity",
+                worktree_path="/tmp/mine",
+            )
+        self.assertIn("Recovery review is required", blocked or "")
 
     def test_same_owner_lease_conflict_allows_refresh(self):
         worktree = "/tmp/wt-420"