fix: persist API delegation units once without waking the model

hermes_state_messages.py

@@ -307,6 +307,38 @@ class SessionMessagesMixin:
         # holding the lock for seconds (VACUUM, checkpoint) can't kill it.
         return self._execute_write(_do, patience_s=self._TRANSCRIPT_WRITE_PATIENCE_S)
 
+    def append_delegation_delivery(self, session_id: str, content: str, metadata: Dict[str, Any]) -> int:
+        """Record a detached API result once, between client turns, including replay after rotation.
+
+        The event's unit id, not its text or active flag, is the identity. Check and insert
+        share the writer transaction, so independent gateway processes cannot duplicate it.
+        """
+        delegation_id = metadata.get("delegation_id")
+        if not delegation_id:
+            raise ValueError("Delegation delivery requires a stable delegation_id")
+        msg = {"content": content, "display_kind": "async_delegation_complete", "display_metadata": metadata}
+        params = self._message_row_params(session_id, "user", msg, None, time.time(), keep_reasoning=True)
+
+        def _do(conn):
+            existing = conn.execute(
+                """WITH RECURSIVE lineage(id) AS (
+                    SELECT ? UNION
+                    SELECT s.parent_session_id FROM sessions s JOIN lineage l ON s.id = l.id
+                    JOIN sessions p ON p.id = s.parent_session_id WHERE p.end_reason = 'compression'
+                ) SELECT m.id FROM messages m JOIN lineage l ON m.session_id = l.id
+                WHERE m.display_kind = 'async_delegation_complete'
+                AND json_extract(m.display_metadata, '$.delegation_id') = ?
+                AND coalesce(json_extract(m.display_metadata, '$.delivery_notice'), '') = ? LIMIT 1""",
+                (session_id, delegation_id, metadata.get("delivery_notice", ""))).fetchone()
+            if existing is not None:
+                return existing[0]
+            self._check_transcript_write_guards(conn, session_id, None, reject_active_turn_lease=True)
+            msg_id = conn.execute(_INSERT_MESSAGE_SQL, params).lastrowid
+            self._bump_session_counters(conn, session_id, 1, 0, unit=True)
+            return msg_id
+
+        return self._execute_write(_do, patience_s=self._TRANSCRIPT_WRITE_PATIENCE_S)
+
     def append_messages_batch(
         self, session_id: str, messages: List[Dict[str, Any]], compression_lock_holder: Optional[str] = None,
         turn_lease_holder: Optional[str] = None, chunk_rows: Optional[int] = None,