fix: enhance proxy configuration with password preservation and UI improvements

- Add 'enabled' field to ProxyConfig for preserving config when disabled
- Mask proxy password in API responses (return '***' instead of actual password)
- Preserve existing password on update when new password not provided
- Add URL encoding for proxy credentials (handle special chars like @, :, /)
- Enhanced URL validation: block SOCKS4, require valid host, forbid embedded auth
- UI improvements: use Switch component, dynamic password placeholder
- Add confirmation dialog for orphaned credentials (URL empty but has username/password)
- Prevent browser password autofill with randomized IDs and CSS text-security
- Unify ProxyConfig type definition in types.ts

src/clients/http_client.py

@@ -5,7 +5,7 @@
 
 from contextlib import asynccontextmanager
 from typing import Any, Dict, Optional
-from urllib.parse import urlparse
+from urllib.parse import quote, urlparse
 
 import httpx
 
@@ -17,14 +17,19 @@ def build_proxy_url(proxy_config: Dict[str, Any]) -> Optional[str]:
     根据代理配置构建完整的代理 URL
 
     Args:
-        proxy_config: 代理配置字典，包含 url, username, password
+        proxy_config: 代理配置字典，包含 url, username, password, enabled
 
     Returns:
         完整的代理 URL，如 socks5://user:pass@host:port
+        如果 enabled=False 或无配置，返回 None
     """
     if not proxy_config:
         return None
 
+    # 检查 enabled 字段，默认为 True（兼容旧数据）
+    if not proxy_config.get("enabled", True):
+        return None
+
     proxy_url = proxy_config.get("url")
     if not proxy_url:
         return None
@@ -32,10 +37,17 @@ def build_proxy_url(proxy_config: Dict[str, Any]) -> Optional[str]:
     username = proxy_config.get("username")
     password = proxy_config.get("password")
 
-    if username and password:
+    # 只要有用户名就添加认证信息（密码可以为空）
+    if username:
         parsed = urlparse(proxy_url)
+        # URL 编码用户名和密码，处理特殊字符（如 @, :, /）
+        encoded_username = quote(username, safe="")
+        encoded_password = quote(password, safe="") if password else ""
         # 重新构建带认证的代理 URL
-        auth_proxy = f"{parsed.scheme}://{username}:{password}@{parsed.netloc}"
+        if encoded_password:
+            auth_proxy = f"{parsed.scheme}://{encoded_username}:{encoded_password}@{parsed.netloc}"
+        else:
+            auth_proxy = f"{parsed.scheme}://{encoded_username}@{parsed.netloc}"
         if parsed.path:
             auth_proxy += parsed.path
         return auth_proxy