fix(flush_memories): strip temperature from codex_responses fallback (#15620)

The memory-flush fallback for api_mode='codex_responses' was unconditionally
adding `temperature` to codex_kwargs before calling _run_codex_stream. The
Responses API does not accept temperature on any supported backend:

- chatgpt.com/backend-api/codex rejects it outright
- api.openai.com + gpt-5/o-series reasoning models reject it
- Copilot Responses rejects it on reasoning models

The CodexAuxiliaryClient adapter and the codex_responses transport both
correctly omit temperature — the flush fallback was the only path putting
it back. On errors from the primary aux path (e.g. expired OAuth token),
users saw `⚠ Auxiliary memory flush failed: HTTP 400: Unsupported parameter:
temperature`.

Reported by Garik [NOUS] on GPT-5.5 via Codex OAuth Pro.

run_agent.py

@@ -8010,17 +8010,20 @@ class AIAgent:
                 response = None
 
             if not _aux_available and self.api_mode == "codex_responses":
-                # No auxiliary client -- use the Codex Responses path directly
+                # No auxiliary client -- use the Codex Responses path directly.
+                # The Responses API does not accept `temperature` on any
+                # supported backend (chatgpt.com/backend-api/codex rejects it
+                # outright; api.openai.com + gpt-5/o-series reasoning models
+                # and Copilot Responses reject it on reasoning models). The
+                # transport intentionally never sets it — strip any leftover
+                # here so the flush fallback matches the main-loop behavior.
                 codex_kwargs = self._build_api_kwargs(api_messages)
                 _ct_flush = self._get_transport()
                 if _ct_flush is not None:
                     codex_kwargs["tools"] = _ct_flush.convert_tools([memory_tool_def])
                 elif not codex_kwargs.get("tools"):
                     codex_kwargs["tools"] = [memory_tool_def]
-                if _flush_temperature is not None:
-                    codex_kwargs["temperature"] = _flush_temperature
-                else:
-                    codex_kwargs.pop("temperature", None)
+                codex_kwargs.pop("temperature", None)
                 if "max_output_tokens" in codex_kwargs:
                     codex_kwargs["max_output_tokens"] = 5120
                 response = self._run_codex_stream(codex_kwargs)