feat: Enhance Claude default max tokens configuration

- Replace ThinkingAdapterMaxTokens with a more flexible DefaultMaxTokens map
- Add support for model-specific default max tokens configuration
- Update relay and web interface to use the new configuration approach
- Implement a fallback mechanism for default max tokens

relay/channel/claude/relay-claude.go

@@ -95,7 +95,7 @@ func RequestOpenAI2ClaudeMessage(textRequest dto.GeneralOpenAIRequest) (*ClaudeR
 	}
 
 	if claudeRequest.MaxTokens == 0 {
-		claudeRequest.MaxTokens = uint(model_setting.GetClaudeSettings().ThinkingAdapterMaxTokens)
+		claudeRequest.MaxTokens = uint(model_setting.GetClaudeSettings().GetDefaultMaxTokens(textRequest.Model))
 	}
 
 	if model_setting.GetClaudeSettings().ThinkingAdapterEnabled &&