Refactor config system to use Pydantic validation

Refactored configuration classes to inherit from a new ValidatedConfigBase using Pydantic for robust validation and error reporting. Updated api_ada_configs.py, config.py, config_base.py, and official_configs.py to replace dataclasses with Pydantic models, add field validation, and improve error messages. This change enhances configuration reliability and developer feedback for misconfigurations. Also includes minor code cleanups and removal of unused variables in other modules.

src/chat/utils/utils_video.py

@@ -169,7 +169,7 @@ class VideoAnalyzer:
             prompt += f"\n\n用户问题: {user_question}"
         
         # 添加帧信息到提示词
-        for i, (frame_base64, timestamp) in enumerate(frames):
+        for i, (_frame_base64, timestamp) in enumerate(frames):
             if self.enable_frame_timing:
                 prompt += f"\n\n第{i+1}帧 (时间: {timestamp:.2f}s):"