feat: add HTTP/SOCKS5 proxy support for API endpoints

- Add proxy field to ProviderEndpoint database model with migration
- Add ProxyConfig Pydantic model for proxy URL validation
- Extend HTTP client pool with create_client_with_proxy method
- Integrate proxy configuration in chat_handler_base.py and cli_handler_base.py
- Update admin API endpoints to support proxy configuration CRUD
- Add proxy configuration UI in frontend EndpointFormDialog

Fixes #28

src/models/admin_requests.py

@@ -13,6 +13,23 @@ from pydantic import BaseModel, Field, field_validator, model_validator
 from src.core.enums import APIFormat, ProviderBillingType
 
 
+class ProxyConfig(BaseModel):
+    """代理配置"""
+
+    url: str = Field(..., description="代理 URL (http://, https://, socks5://)")
+    username: Optional[str] = Field(None, max_length=255, description="代理用户名")
+    password: Optional[str] = Field(None, max_length=500, description="代理密码")
+
+    @field_validator("url")
+    @classmethod
+    def validate_proxy_url(cls, v: str) -> str:
+        """验证代理 URL 格式"""
+        v = v.strip()
+        if not re.match(r"^(http|https|socks5|socks4)://", v, re.IGNORECASE):
+            raise ValueError("代理 URL 必须以 http://, https://, socks5:// 或 socks4:// 开头")
+        return v
+
+
 class CreateProviderRequest(BaseModel):
     """创建 Provider 请求"""
 
@@ -165,6 +182,7 @@ class CreateEndpointRequest(BaseModel):
     rpm_limit: Optional[int] = Field(None, ge=0, description="RPM 限制")
     concurrent_limit: Optional[int] = Field(None, ge=0, description="并发限制")
     config: Optional[Dict[str, Any]] = Field(None, description="其他配置")
+    proxy: Optional[ProxyConfig] = Field(None, description="代理配置")
 
     @field_validator("name")
     @classmethod
@@ -220,6 +238,7 @@ class UpdateEndpointRequest(BaseModel):
     rpm_limit: Optional[int] = Field(None, ge=0)
     concurrent_limit: Optional[int] = Field(None, ge=0)
     config: Optional[Dict[str, Any]] = None
+    proxy: Optional[ProxyConfig] = Field(None, description="代理配置")
 
     # 复用验证器
     _validate_name = field_validator("name")(CreateEndpointRequest.validate_name.__func__)

src/models/database.py

@@ -538,6 +538,9 @@ class ProviderEndpoint(Base):
     # 额外配置
     config = Column(JSON, nullable=True)  # 端点特定配置（不推荐使用，优先使用专用字段）
 
+    # 代理配置
+    proxy = Column(JSONB, nullable=True)  # 代理配置: {url, username, password}
+
     # 时间戳
     created_at = Column(
         DateTime(timezone=True), default=lambda: datetime.now(timezone.utc), nullable=False

src/models/endpoint_models.py

@@ -8,6 +8,8 @@ from typing import Any, Dict, List, Optional
 
 from pydantic import BaseModel, ConfigDict, Field, field_validator
 
+from src.models.admin_requests import ProxyConfig
+
 # ========== ProviderEndpoint CRUD ==========
 
 
@@ -30,6 +32,9 @@ class ProviderEndpointCreate(BaseModel):
     # 额外配置
     config: Optional[Dict[str, Any]] = Field(default=None, description="额外配置（JSON）")
 
+    # 代理配置
+    proxy: Optional[ProxyConfig] = Field(default=None, description="代理配置")
+
     @field_validator("api_format")
     @classmethod
     def validate_api_format(cls, v: str) -> str:
@@ -64,6 +69,7 @@ class ProviderEndpointUpdate(BaseModel):
     rate_limit: Optional[int] = Field(default=None, ge=1, description="速率限制")
     is_active: Optional[bool] = Field(default=None, description="是否启用")
     config: Optional[Dict[str, Any]] = Field(default=None, description="额外配置")
+    proxy: Optional[ProxyConfig] = Field(default=None, description="代理配置")
 
     @field_validator("base_url")
     @classmethod
@@ -104,6 +110,9 @@ class ProviderEndpointResponse(BaseModel):
     # 额外配置
     config: Optional[Dict[str, Any]] = None
 
+    # 代理配置
+    proxy: Optional[Dict[str, Any]] = Field(default=None, description="代理配置")
+
     # 统计（从 Keys 聚合）
     total_keys: int = Field(default=0, description="总 Key 数量")
     active_keys: int = Field(default=0, description="活跃 Key 数量")