feat: persist MCP workflow proof and decision lock across daemons (Closes #559)

Share review-workflow-load and review-decision-lock state across MCP
daemon process pools via a user-private durable store keyed by profile
identity (not host-global /tmp), with TTL and fail-closed profile checks.

tests/test_review_workflow_load.py

@@ -33,12 +33,38 @@ class TestReviewWorkflowLoadModule(unittest.TestCase):
         self.assertTrue(status["workflow_load_proof_present"])
         self.assertTrue(status["workflow_load_valid"])
 
-    def test_stale_session_pid_blocks(self):
+    def test_profile_identity_mismatch_blocks(self):
+        """#559: different daemon PIDs are OK; profile identity mismatch is not."""
+        import tempfile
+        from unittest.mock import patch
+
+        import mcp_session_state
+
         root = str(__import__("pathlib").Path(__file__).resolve().parent.parent)
-        review_workflow_load.record_review_workflow_load(root)
-        review_workflow_load._REVIEW_WORKFLOW_LOAD["session_pid"] = 0
-        blockers = review_workflow_load.review_workflow_load_blockers(root)
-        self.assertTrue(any("different process" in b for b in blockers))
+        with tempfile.TemporaryDirectory() as tmp:
+            with patch.dict(
+                os.environ,
+                {
+                    mcp_session_state.STATE_DIR_ENV: tmp,
+                    mcp_session_state.SESSION_PROFILE_LOCK_ENV: "prgs-reviewer",
+                },
+                clear=False,
+            ):
+                review_workflow_load.clear_review_workflow_load()
+                review_workflow_load.record_review_workflow_load(root)
+                # Corrupt the in-memory profile identity while keeping PID.
+                review_workflow_load._REVIEW_WORKFLOW_LOAD[
+                    "session_profile_lock"
+                ] = "other-profile"
+                review_workflow_load._REVIEW_WORKFLOW_LOAD[
+                    "profile_identity"
+                ] = "other-profile"
+                blockers = review_workflow_load.review_workflow_load_blockers(root)
+                self.assertTrue(
+                    any("profile identity mismatch" in b for b in blockers),
+                    msg=blockers,
+                )
+                review_workflow_load.clear_review_workflow_load()
 
     def test_prompt_conflict_detected(self):
         conflict, reasons = review_workflow_load.assess_prompt_conflict(