Add production condition retrieval smoke test

apps/ai-service/adapters/postgres.py

@@ -23,6 +23,10 @@ class RetrievalTrace:
     created_at: datetime | None = None
 
 
+class FeedbackTraceNotFound(LookupError):
+    """The answer trace was never persisted, so feedback cannot be linked."""
+
+
 class PostgresTraceRepository:
     """Opens a new connection per call — no pooling (F-09: a real pool, with
     startup-time lifecycle, is a further improvement not made here).
@@ -102,6 +106,39 @@ class PostgresTraceRepository:
             created_at=row[10],
         )
 
+    def save_feedback(
+        self,
+        *,
+        trace_id: str,
+        rating: str,
+        comment: str | None,
+        conversation_id: str | None,
+    ) -> str:
+        """Create or replace one user's verdict for one persisted answer."""
+        import psycopg
+
+        feedback_id = str(uuid.uuid4())
+        with psycopg.connect(self._dsn, connect_timeout=5) as connection:
+            row = connection.execute(
+                """
+                INSERT INTO rag_answer_feedback (
+                    feedback_id, trace_id, conversation_id, rating, comment
+                )
+                SELECT %s, trace_id, %s, %s, %s
+                FROM rag_retrieval_trace WHERE trace_id = %s
+                ON CONFLICT (trace_id) DO UPDATE SET
+                    conversation_id = EXCLUDED.conversation_id,
+                    rating = EXCLUDED.rating,
+                    comment = EXCLUDED.comment,
+                    updated_at = now()
+                RETURNING feedback_id::text
+                """,
+                (feedback_id, conversation_id, rating, comment, trace_id),
+            ).fetchone()
+        if row is None:
+            raise FeedbackTraceNotFound(trace_id)
+        return str(row[0])
+
 
 class PostgresConversationStore:
     """Durable, cross-worker replacement for `RagAgent`'s in-process