fix(config): 调整熔断恢复超时时间为 30 秒;

将 vendors.openai.circuit_breaker.recovery_timeout_seconds
从 300 秒缩短至 30 秒，加快故障恢复检测频率。

🤖 Generated with [Claude Code](https://github.com/claude), [CodeX](https://openai.com), [Gemini](https://github.com/apps/gemini-code-assist)
Co-Authored-By: Aurelius Huang<threefish.ai@gmail.com>

Author: ThreeFish-AI

src/coding/proxy/config/config.default.yaml

@@ -111,7 +111,7 @@ vendors:
     # 不配置 circuit_breaker → 自动成为终端层，不触发向下故障转移
     circuit_breaker:
       failure_threshold: 3
-      recovery_timeout_seconds: 300
+      recovery_timeout_seconds: 30
       success_threshold: 2
     quota_guard:
       enabled: true # 启用后按 Premium Requests 配额管理