feat: add support for DouBao, Ernie, Kimi, Qwen, ZhiPu LLM providers

Introduces new provider modules for DouBao, Ernie, Kimi, Qwen, and ZhiPu, and registers them in the LLM registry. Updates documentation and .env.example to include configuration instructions for these providers. Refactors OpenAI provider to support OpenAI-compatible endpoints. Adds @ai-sdk/openai-compatible and node-fetch dependencies.

app/lib/.server/logger.server.ts

@@ -22,7 +22,7 @@ let currentLevel: DebugLevel =
   (process.env.LOG_LEVEL as DebugLevel | undefined) || (import.meta.env.DEV ? 'debug' : 'info');
 
 // 文件日志配置
-const enableFileLogging = process.env.USAGE_LOG_FILE === 'true' || import.meta.env.DEV;
+const enableFileLogging = process.env.USAGE_LOG_FILE !== 'false';
 const logDir = path.join(process.cwd(), 'logs');
 
 // 确保日志目录存在