feat: add additional response info to llm gateway response (#467)

Author: m-ods

llm-gateway.yml

@@ -302,6 +302,18 @@ components:
               $ref: "#/components/schemas/ToolChoice"
         usage:
           $ref: "#/components/schemas/Usage"
+        http_status_code:
+          type: integer
+          description: The HTTP status code of the response
+          example: 200
+        response_time:
+          type: integer
+          description: The response time in nanoseconds
+          example: 275510459
+        llm_status_code:
+          type: integer
+          description: The status code from the LLM provider
+          example: 200
 
     Choice:
       type: object