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/service/proxy/__init__.py

@@ -0,0 +1,7 @@
+"""
+Proxy service module
+"""
+
+from .proxy_check_service import ProxyCheckService
+
+__all__ = ["ProxyCheckService"] 

app/service/proxy/proxy_check_service.py

@@ -0,0 +1,219 @@
+"""
+Proxy detection service module
+"""
+import asyncio
+import time
+from typing import Dict, List, Optional, Tuple
+from urllib.parse import urlparse
+
+import httpx
+from pydantic import BaseModel
+
+from app.log.logger import get_config_routes_logger
+
+logger = get_config_routes_logger()
+
+
+class ProxyCheckResult(BaseModel):
+    """Proxy check result model"""
+    proxy: str
+    is_available: bool
+    response_time: Optional[float] = None
+    error_message: Optional[str] = None
+    checked_at: float
+
+
+class ProxyCheckService:
+    """Proxy detection service class"""
+    
+    # Target URL for checking
+    CHECK_URL = "https://www.google.com"
+    # Timeout in seconds
+    TIMEOUT_SECONDS = 10
+    # Cache duration in seconds
+    CACHE_DURATION = 10  # 10s
+    
+    def __init__(self):
+        self._cache: Dict[str, ProxyCheckResult] = {}
+    
+    def _is_valid_proxy_format(self, proxy: str) -> bool:
+        """Validate proxy format"""
+        try:
+            parsed = urlparse(proxy)
+            return parsed.scheme in ['http', 'https', 'socks5'] and parsed.hostname
+        except Exception:
+            return False
+    
+    def _get_cached_result(self, proxy: str) -> Optional[ProxyCheckResult]:
+        """Get cached check result"""
+        if proxy in self._cache:
+            result = self._cache[proxy]
+            # Check if cache is expired
+            if time.time() - result.checked_at < self.CACHE_DURATION:
+                logger.debug(f"Using cached proxy check result: {proxy}")
+                return result
+            else:
+                # Remove expired cache
+                del self._cache[proxy]
+        return None
+    
+    def _cache_result(self, result: ProxyCheckResult) -> None:
+        """Cache check result"""
+        self._cache[result.proxy] = result
+    
+    async def check_single_proxy(self, proxy: str, use_cache: bool = True) -> ProxyCheckResult:
+        """
+        Check if a single proxy is available
+        
+        Args:
+            proxy: Proxy address in format like http://host:port or socks5://host:port
+            use_cache: Whether to use cached results
+            
+        Returns:
+            ProxyCheckResult: Check result
+        """
+        # Check cache first
+        if use_cache:
+            cached = self._get_cached_result(proxy)
+            if cached:
+                return cached
+        
+        # Validate proxy format
+        if not self._is_valid_proxy_format(proxy):
+            result = ProxyCheckResult(
+                proxy=proxy,
+                is_available=False,
+                error_message="Invalid proxy format",
+                checked_at=time.time()
+            )
+            self._cache_result(result)
+            return result
+        
+        # Perform check
+        start_time = time.time()
+        try:
+            logger.info(f"Starting proxy check: {proxy}")
+            
+            timeout = httpx.Timeout(self.TIMEOUT_SECONDS, read=self.TIMEOUT_SECONDS)
+            async with httpx.AsyncClient(timeout=timeout, proxy=proxy) as client:
+                response = await client.head(self.CHECK_URL)
+                
+            response_time = time.time() - start_time
+            
+            # Check response status
+            is_available = response.status_code in [200, 204, 301, 302, 307, 308]
+            
+            result = ProxyCheckResult(
+                proxy=proxy,
+                is_available=is_available,
+                response_time=round(response_time, 3),
+                error_message=None if is_available else f"HTTP {response.status_code}",
+                checked_at=time.time()
+            )
+            
+            logger.info(f"Proxy check completed: {proxy}, available: {is_available}, response_time: {response_time:.3f}s")
+            
+        except asyncio.TimeoutError:
+            result = ProxyCheckResult(
+                proxy=proxy,
+                is_available=False,
+                error_message="Connection timeout",
+                checked_at=time.time()
+            )
+            logger.warning(f"Proxy check timeout: {proxy}")
+            
+        except Exception as e:
+            result = ProxyCheckResult(
+                proxy=proxy,
+                is_available=False,
+                error_message=str(e),
+                checked_at=time.time()
+            )
+            logger.error(f"Proxy check failed: {proxy}, error: {str(e)}")
+        
+        # Cache result
+        self._cache_result(result)
+        return result
+    
+    async def check_multiple_proxies(
+        self, 
+        proxies: List[str], 
+        use_cache: bool = True,
+        max_concurrent: int = 5
+    ) -> List[ProxyCheckResult]:
+        """
+        Check multiple proxies concurrently
+        
+        Args:
+            proxies: List of proxy addresses
+            use_cache: Whether to use cached results
+            max_concurrent: Maximum concurrent check count
+            
+        Returns:
+            List[ProxyCheckResult]: List of check results
+        """
+        if not proxies:
+            return []
+        
+        logger.info(f"Starting batch proxy check for {len(proxies)} proxies")
+        
+        # Use semaphore to limit concurrency
+        semaphore = asyncio.Semaphore(max_concurrent)
+        
+        async def check_with_semaphore(proxy: str) -> ProxyCheckResult:
+            async with semaphore:
+                return await self.check_single_proxy(proxy, use_cache)
+        
+        # Execute checks concurrently
+        tasks = [check_with_semaphore(proxy) for proxy in proxies]
+        results = await asyncio.gather(*tasks, return_exceptions=True)
+        
+        # Handle exception results
+        final_results = []
+        for i, result in enumerate(results):
+            if isinstance(result, Exception):
+                logger.error(f"Proxy check task exception: {proxies[i]}, error: {str(result)}")
+                final_results.append(ProxyCheckResult(
+                    proxy=proxies[i],
+                    is_available=False,
+                    error_message=f"Check task exception: {str(result)}",
+                    checked_at=time.time()
+                ))
+            else:
+                final_results.append(result)
+        
+        available_count = sum(1 for r in final_results if r.is_available)
+        logger.info(f"Batch proxy check completed: {available_count}/{len(proxies)} proxies available")
+        
+        return final_results
+    
+    def get_cache_stats(self) -> Dict[str, int]:
+        """Get cache statistics"""
+        current_time = time.time()
+        valid_cache_count = sum(
+            1 for result in self._cache.values()
+            if current_time - result.checked_at < self.CACHE_DURATION
+        )
+        
+        return {
+            "total_cached": len(self._cache),
+            "valid_cached": valid_cache_count,
+            "expired_cached": len(self._cache) - valid_cache_count
+        }
+    
+    def clear_cache(self) -> None:
+        """Clear all cache"""
+        self._cache.clear()
+        logger.info("Proxy check cache cleared")
+
+
+# Global instance
+_proxy_check_service: Optional[ProxyCheckService] = None
+
+
+def get_proxy_check_service() -> ProxyCheckService:
+    """Get proxy check service instance"""
+    global _proxy_check_service
+    if _proxy_check_service is None:
+        _proxy_check_service = ProxyCheckService()
+    return _proxy_check_service