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/conftest.py

@@ -18,14 +18,25 @@ def _reset_mutation_authority(monkeypatch):
     explicitly.
     """
     monkeypatch.delenv("GITEA_SESSION_PROFILE_LOCK", raising=False)
+    # Isolate durable session-state files so tests never share host cache (#559).
+    import tempfile
+
+    _state_tmp = tempfile.TemporaryDirectory(prefix="gitea-session-state-")
+    monkeypatch.setenv("GITEA_MCP_SESSION_STATE_DIR", _state_tmp.name)
     try:
         import mcp_server
     except Exception:
+        _state_tmp.cleanup()
         yield
         return
     monkeypatch.setattr(mcp_server, "_MUTATION_AUTHORITY", None)
     monkeypatch.setattr(mcp_server, "_IDENTITY_CACHE", {})
     monkeypatch.setattr(mcp_server, "_REVIEW_DECISION_LOCK", None)
+    try:
+        import review_workflow_load
+        review_workflow_load._REVIEW_WORKFLOW_LOAD = None
+    except Exception:
+        pass
     try:
         import capability_stop_terminal
         capability_stop_terminal.clear()
@@ -37,3 +48,13 @@ def _reset_mutation_authority(monkeypatch):
         capability_stop_terminal.clear()
     except Exception:
         pass
+    try:
+        import review_workflow_load
+        review_workflow_load._REVIEW_WORKFLOW_LOAD = None
+    except Exception:
+        pass
+    try:
+        mcp_server._REVIEW_DECISION_LOCK = None
+    except Exception:
+        pass
+    _state_tmp.cleanup()