fix: ensure token usage recording, validate response model on stream

lib/crewai/tests/cassettes/agents/test_llm_call.yaml

@@ -40,22 +40,12 @@ interactions:
     uri: https://api.openai.com/v1/chat/completions
   response:
     body:
-      string: !!binary |
-        H4sIAAAAAAAAAwAAAP//jJJBT+MwEIXv+RXeOacVpe2y9AoHjsCl0qIqcu1pYnA8xp4AW9T/juyW
-        JrAgcfHB37zxe+N5LYQAo2EhQDWSVevt6OL+krfL6+3NY91Onp8vrv7Wze3TOqrti1tCmRS0vkfF
-        76qxotZbZENuj1VAyZi6Ts5+z/6cz06n8wxa0miTrPY8mo7nI+7CmkYnk9P5QdmQURhhIe4KIYR4
-        zWfy6DS+wEKclO83LcYoa4TFsUgICGTTDcgYTWTpGMoeKnKMLtu+QmupFEsKVv8a1gTcdFEmj66z
-        dgCkc8QyZczuVgeyO/qxVPtA6/hJChvjTGyqgDKSS29HJg+Z7gohVjl39yEK+ECt54rpAfNzk+m+
-        HfST7uHswJhY2oHmrPyiWaWRpbFxMDZQUjWoe2U/Y9lpQwNQDCL/7+Wr3vvYxtU/ad8DpdAz6soH
-        1EZ9zNuXBUxr+F3ZccTZMEQMT0ZhxQZD+gaNG9nZ/YJA/BcZ22pjXI3BB5O3JH1jsSveAAAA//8D
-        AHtQ27QkAwAA
+      string: "{\n  \"id\": \"chatcmpl-CjDtzWPzQqgm1wwCHZghRvbsczxnW\",\n  \"object\": \"chat.completion\",\n  \"created\": 1764894235,\n  \"model\": \"gpt-3.5-turbo-0125\",\n  \"choices\": [\n    {\n      \"index\": 0,\n      \"message\": {\n        \"role\": \"assistant\",\n        \"content\": \"Hello, World!\",\n        \"refusal\": null,\n        \"annotations\": []\n      },\n      \"logprobs\": null,\n      \"finish_reason\": \"stop\"\n    }\n  ],\n  \"usage\": {\n    \"prompt_tokens\": 13,\n    \"completion_tokens\": 4,\n    \"total_tokens\": 17,\n    \"prompt_tokens_details\": {\n      \"cached_tokens\": 0,\n      \"audio_tokens\": 0\n    },\n    \"completion_tokens_details\": {\n      \"reasoning_tokens\": 0,\n      \"audio_tokens\": 0,\n      \"accepted_prediction_tokens\": 0,\n      \"rejected_prediction_tokens\": 0\n    }\n  },\n  \"service_tier\": \"default\",\n  \"system_fingerprint\": null\n}\n"
     headers:
       CF-RAY:
       - CF-RAY-XXX
       Connection:
       - keep-alive
-      Content-Encoding:
-      - gzip
       Content-Type:
       - application/json
       Date: