fix(aux): surface auxiliary failures in UI

tests/run_agent/test_flush_memories_codex.py

@@ -188,6 +188,30 @@ class TestFlushMemoriesUsesAuxiliaryClient:
 
         agent.client.chat.completions.create.assert_called_once()
 
+    def test_auxiliary_provider_failure_surfaces_warning_and_falls_back(self, monkeypatch):
+        """Provider/API failures from auxiliary flush must be visible.
+
+        Exhausted keys and rate limits are not always RuntimeError. They used
+        to fall into the broad outer handler and disappear into debug logs.
+        """
+        agent = _make_agent(monkeypatch, api_mode="chat_completions", provider="openrouter")
+        agent.client = MagicMock()
+        agent.client.chat.completions.create.return_value = _chat_response_with_memory_call()
+        events = []
+        agent.status_callback = lambda kind, text=None: events.append((kind, text))
+
+        with patch("agent.auxiliary_client.call_llm", side_effect=Exception("opencode-go key exhausted")), \
+             patch("tools.memory_tool.memory_tool", return_value="Saved."):
+            messages = [
+                {"role": "user", "content": "Hello"},
+                {"role": "assistant", "content": "Hi there"},
+                {"role": "user", "content": "Save this"},
+            ]
+            agent.flush_memories(messages)
+
+        agent.client.chat.completions.create.assert_called_once()
+        assert any(kind == "warn" and "Auxiliary memory flush failed" in text for kind, text in events)
+
     def test_flush_executes_memory_tool_calls(self, monkeypatch):
         """Verify that memory tool calls from the flush response actually get executed."""
         agent = _make_agent(monkeypatch, api_mode="chat_completions", provider="openrouter")