feat: add _should_sanitize_tool_calls() method

Adds a centralized method to determine when tool_calls need sanitization
for strict APIs. Returns True for all APIs except codex_responses mode.
This prevents 400 errors from providers like Fireworks that reject unknown
fields (call_id, response_item_id) in tool_calls.

run_agent.py

@@ -5345,6 +5345,19 @@ class AIAgent:
         ]
         return api_msg
 
+    def _should_sanitize_tool_calls(self) -> bool:
+        """Determine if tool_calls need sanitization for strict APIs.
+
+        Codex Responses API uses fields like call_id and response_item_id
+        that are not part of the standard Chat Completions schema. These
+        fields must be stripped when calling any other API to avoid
+        validation errors (400 Bad Request).
+
+        Returns:
+            bool: True if sanitization is needed (non-Codex API), False otherwise.
+        """
+        return self.api_mode != "codex_responses"
+
     def flush_memories(self, messages: list = None, min_turns: int = None):
         """Give the model one turn to persist memories before context is lost.