feat: 实现代理健康检查功能

添加完整的代理检测系统，包括：

后端功能：
- 新增代理检测服务模块 (app/service/proxy/)
  * ProxyCheckService: 核心检测逻辑，支持HTTP/HTTPS/SOCKS5代理
  * 内置缓存机制，避免重复检测 (10秒缓存期)
  * 支持并发检测，可配置最大并发数
- 新增4个API端点 (app/router/config_routes.py):
  * POST /api/config/proxy/check - 单个代理检测
  * POST /api/config/proxy/check-all - 批量代理检测
  * GET /api/config/proxy/cache-stats - 缓存统计
  * POST /api/config/proxy/clear-cache - 清空缓存

前端功能：
- 代理列表中每项添加状态图标和检测按钮
- 支持单个代理实时检测
- 新增检测所有代理功能按钮
- 代理检测结果模态框，显示：
  * 检测进度条和状态
  * 可用/不可用代理统计
  * 详细的检测结果列表（响应时间、错误信息）
  * 重试失败代理功能

技术特性：
- 10秒超时机制，避免长时间等待
- 异步并发检测，提升批量检测效率
- 缓存机制减少重复请求
- 完整的错误处理和用户友好提示
- 响应式UI设计，支持实时状态更新

app/router/config_routes.py

@@ -11,6 +11,7 @@ from pydantic import BaseModel, Field
 from app.core.security import verify_auth_token
 from app.log.logger import Logger, get_config_routes_logger
 from app.service.config.config_service import ConfigService
+from app.service.proxy.proxy_check_service import get_proxy_check_service, ProxyCheckResult
 from app.utils.helpers import redact_key_for_logging
 
 router = APIRouter(prefix="/api/config", tags=["config"])
@@ -132,3 +133,93 @@ async def get_ui_models(request: Request):
             status_code=500,
             detail=f"An unexpected error occurred while fetching UI models: {str(e)}",
         )
+
+
+class ProxyCheckRequest(BaseModel):
+    """Proxy check request"""
+    proxy: str = Field(..., description="Proxy address to check")
+    use_cache: bool = Field(True, description="Whether to use cached results")
+
+
+class ProxyBatchCheckRequest(BaseModel):
+    """Batch proxy check request"""
+    proxies: List[str] = Field(..., description="List of proxy addresses to check")
+    use_cache: bool = Field(True, description="Whether to use cached results")
+    max_concurrent: int = Field(5, description="Maximum concurrent check count", ge=1, le=10)
+
+
+@router.post("/proxy/check", response_model=ProxyCheckResult)
+async def check_single_proxy(proxy_request: ProxyCheckRequest, request: Request):
+    """Check if a single proxy is available"""
+    auth_token = request.cookies.get("auth_token")
+    if not auth_token or not verify_auth_token(auth_token):
+        logger.warning("Unauthorized access attempt to proxy check")
+        return RedirectResponse(url="/", status_code=302)
+    
+    try:
+        logger.info(f"Checking single proxy: {proxy_request.proxy}")
+        proxy_service = get_proxy_check_service()
+        result = await proxy_service.check_single_proxy(
+            proxy_request.proxy, 
+            proxy_request.use_cache
+        )
+        return result
+    except Exception as e:
+        logger.error(f"Proxy check failed: {str(e)}", exc_info=True)
+        raise HTTPException(status_code=500, detail=f"Proxy check failed: {str(e)}")
+
+
+@router.post("/proxy/check-all", response_model=List[ProxyCheckResult])
+async def check_all_proxies(batch_request: ProxyBatchCheckRequest, request: Request):
+    """Check multiple proxies availability"""
+    auth_token = request.cookies.get("auth_token")
+    if not auth_token or not verify_auth_token(auth_token):
+        logger.warning("Unauthorized access attempt to batch proxy check")
+        return RedirectResponse(url="/", status_code=302)
+    
+    try:
+        logger.info(f"Batch checking {len(batch_request.proxies)} proxies")
+        proxy_service = get_proxy_check_service()
+        results = await proxy_service.check_multiple_proxies(
+            batch_request.proxies,
+            batch_request.use_cache,
+            batch_request.max_concurrent
+        )
+        return results
+    except Exception as e:
+        logger.error(f"Batch proxy check failed: {str(e)}", exc_info=True)
+        raise HTTPException(status_code=500, detail=f"Batch proxy check failed: {str(e)}")
+
+
+@router.get("/proxy/cache-stats")
+async def get_proxy_cache_stats(request: Request):
+    """Get proxy check cache statistics"""
+    auth_token = request.cookies.get("auth_token")
+    if not auth_token or not verify_auth_token(auth_token):
+        logger.warning("Unauthorized access attempt to proxy cache stats")
+        return RedirectResponse(url="/", status_code=302)
+    
+    try:
+        proxy_service = get_proxy_check_service()
+        stats = proxy_service.get_cache_stats()
+        return stats
+    except Exception as e:
+        logger.error(f"Get proxy cache stats failed: {str(e)}", exc_info=True)
+        raise HTTPException(status_code=500, detail=f"Get cache stats failed: {str(e)}")
+
+
+@router.post("/proxy/clear-cache")
+async def clear_proxy_cache(request: Request):
+    """Clear proxy check cache"""
+    auth_token = request.cookies.get("auth_token")
+    if not auth_token or not verify_auth_token(auth_token):
+        logger.warning("Unauthorized access attempt to clear proxy cache")
+        return RedirectResponse(url="/", status_code=302)
+    
+    try:
+        proxy_service = get_proxy_check_service()
+        proxy_service.clear_cache()
+        return {"success": True, "message": "Proxy check cache cleared"}
+    except Exception as e:
+        logger.error(f"Clear proxy cache failed: {str(e)}", exc_info=True)
+        raise HTTPException(status_code=500, detail=f"Clear cache failed: {str(e)}")