fix(mappers): Update reasoning parameter handling in OpenAI mapping

Author: vprashrex

backend/app/services/llm/mappers.py

@@ -70,7 +70,8 @@ def map_kaapi_to_openai_params(
         - instructions → instructions
         - knowledge_base_ids → tools[file_search].vector_store_ids
         - max_num_results → tools[file_search].max_num_results (fallback default)
-        - reasoning → reasoning.effort (if reasoning supported by model else suppressed)
+        - effort → reasoning.effort (if reasoning supported by model else suppressed)
+        - reasoning → legacy alias for effort, used only when effort is absent
         - temperature → temperature (if reasoning not supported by model else suppressed)
 
     Returns:
@@ -83,6 +84,7 @@ def map_kaapi_to_openai_params(
 
     model = kaapi_params.get("model")
     reasoning = kaapi_params.get("reasoning")
+    effort = kaapi_params.get("effort")
     temperature = kaapi_params.get("temperature")
     instructions = kaapi_params.get("instructions")
     knowledge_base_ids = kaapi_params.get("knowledge_base_ids")
@@ -92,21 +94,25 @@ def map_kaapi_to_openai_params(
         session=session, provider="openai", model_name=model
     )
 
+    # 'effort' is the canonical knob; 'reasoning' is a legacy alias kept for
+    # backward compatibility and only consulted when 'effort' is absent
+    effort_value = effort if effort is not None else reasoning
+
     # Handle reasoning vs temperature mutual exclusivity
     if support_reasoning:
-        if reasoning is not None:
-            openai_params["reasoning"] = {"effort": reasoning}
+        if effort_value is not None:
+            openai_params["reasoning"] = {"effort": effort_value}
 
         if temperature is not None:
             warnings.append(
                 "Parameter 'temperature' was suppressed because the selected model "
                 "supports reasoning, and temperature is ignored when reasoning is enabled."
             )
     else:
-        if reasoning is not None:
+        if effort_value is not None:
             warnings.append(
-                "Parameter 'reasoning' was suppressed because the selected model "
-                "does not support reasoning."
+                "Parameters 'reasoning'/'effort' were suppressed because the "
+                "selected model does not support reasoning."
             )
 
         if temperature is not None: