feat: OAuth 绑定安全增强及限流配置优化

- 新增一次性绑定令牌机制，避免在 URL 中暴露 access_token
- 绑定流程改为新标签页打开，完成后自动刷新状态
- 放宽认证相关接口的 IP 限流配置
- 登录添加 429 限流错误的友好提示
- OAuth 绑定列表添加 Provider 图标显示

Close #106

src/api/oauth/user.py

@@ -2,24 +2,30 @@
 
 from __future__ import annotations
 
-from typing import Any, cast
+from typing import Any, Optional, cast
 
-from fastapi import APIRouter, Depends, Request, status
+from fastapi import APIRouter, Depends, HTTPException, Request, status
 from sqlalchemy.orm import Session
 from starlette.responses import RedirectResponse
 
+from src.api.base.adapter import ApiMode
 from src.api.base.authenticated_adapter import AuthenticatedApiAdapter
 from src.api.base.context import ApiRequestContext
 from src.api.base.pipeline import ApiRequestPipeline
+from src.clients.redis_client import get_redis_client
 from src.database import get_db
+from src.models.database import User
 from src.services.auth.oauth.service import OAuthService
+from src.services.auth.oauth.state import consume_oauth_bind_token, create_oauth_bind_token
 
 router = APIRouter(prefix="/api/user/oauth", tags=["User - OAuth"])
 pipeline = ApiRequestPipeline()
 
 
 @router.get("/bindable-providers")
-async def list_bindable_providers(request: Request, db: Session = Depends(get_db)) -> dict[str, Any]:
+async def list_bindable_providers(
+    request: Request, db: Session = Depends(get_db)
+) -> dict[str, Any]:
     adapter = ListBindableProvidersAdapter()
     result = await pipeline.run(adapter=adapter, http_request=request, db=db, mode=adapter.mode)
     return cast(dict[str, Any], result)
@@ -32,11 +38,25 @@ async def list_my_oauth_links(request: Request, db: Session = Depends(get_db)) -
     return cast(dict[str, Any], result)
 
 
+@router.post("/{provider_type}/bind-token")
+async def create_bind_token(
+    provider_type: str, request: Request, db: Session = Depends(get_db)
+) -> dict[str, Any]:
+    """创建一次性 OAuth 绑定令牌，用于浏览器跳转场景的安全认证"""
+    adapter = CreateBindTokenAdapter(provider_type=provider_type)
+    result = await pipeline.run(adapter=adapter, http_request=request, db=db, mode=adapter.mode)
+    return cast(dict[str, Any], result)
+
+
 @router.get("/{provider_type}/bind")
 async def bind_oauth_provider(
-    provider_type: str, request: Request, db: Session = Depends(get_db)
+    provider_type: str,
+    request: Request,
+    db: Session = Depends(get_db),
+    bind_token: Optional[str] = None,
 ) -> RedirectResponse:
-    adapter = BindOAuthProviderAdapter(provider_type=provider_type)
+    """发起 OAuth 绑定流程，支持通过 bind_token 参数进行安全认证"""
+    adapter = BindOAuthProviderAdapter(provider_type=provider_type, bind_token=bind_token)
     result = await pipeline.run(adapter=adapter, http_request=request, db=db, mode=adapter.mode)
     return cast(RedirectResponse, result)
 
@@ -64,13 +84,81 @@ class ListMyOAuthLinksAdapter(AuthenticatedApiAdapter):
         return {"links": links}
 
 
-class BindOAuthProviderAdapter(AuthenticatedApiAdapter):
+class CreateBindTokenAdapter(AuthenticatedApiAdapter):
+    """创建一次性 OAuth 绑定令牌，用于浏览器跳转场景"""
+
     def __init__(self, provider_type: str):
         self.provider_type = provider_type
 
-    async def handle(self, context: ApiRequestContext) -> RedirectResponse:  # type: ignore[override]
+    async def handle(self, context: ApiRequestContext) -> dict[str, Any]:  # type: ignore[override]
         assert context.user is not None
-        url = await OAuthService.build_bind_authorize_url(context.db, context.user, self.provider_type)
+        assert context.user.id is not None
+
+        # 验证 provider 是否存在且可绑定
+        bindable = await OAuthService.list_bindable_providers(context.db, context.user)
+        if not any(p["provider_type"] == self.provider_type for p in bindable):
+            raise HTTPException(status_code=400, detail="无法绑定该 Provider")
+
+        redis = await get_redis_client(require_redis=True)
+        if redis is None:
+            raise HTTPException(status_code=503, detail="Redis 不可用")
+
+        token = await create_oauth_bind_token(
+            redis, user_id=context.user.id, provider_type=self.provider_type
+        )
+        return {"bind_token": token}
+
+
+class BindOAuthProviderAdapter(AuthenticatedApiAdapter):
+    """发起 OAuth 绑定流程，支持两种认证方式：
+    1. Authorization header (标准方式)
+    2. bind_token 参数 (浏览器跳转场景)
+    """
+
+    def __init__(self, provider_type: str, bind_token: Optional[str] = None):
+        self.provider_type = provider_type
+        self.bind_token = bind_token
+        self._user_from_bind_token: Optional[User] = None
+
+    @property
+    def mode(self) -> ApiMode:  # type: ignore[override]
+        # 如果有 bind_token，使用 PUBLIC mode 跳过 header 认证
+        if self.bind_token:
+            return ApiMode.PUBLIC
+        return ApiMode.USER
+
+    def authorize(self, context: ApiRequestContext) -> None:
+        # 如果是 bind_token 模式，不在这里检查（会在 handle 中验证）
+        if self.bind_token:
+            return
+        # 标准模式，检查用户
+        if not context.user:
+            raise HTTPException(status_code=401, detail="未登录")
+
+    async def handle(self, context: ApiRequestContext) -> RedirectResponse:  # type: ignore[override]
+        user: Optional[User] = context.user
+
+        # 如果使用 bind_token，验证并获取用户
+        if self.bind_token:
+            redis = await get_redis_client(require_redis=True)
+            if redis is None:
+                raise HTTPException(status_code=503, detail="Redis 不可用")
+
+            token_data = await consume_oauth_bind_token(redis, self.bind_token)
+            if not token_data:
+                raise HTTPException(status_code=401, detail="无效或过期的绑定令牌")
+
+            # 验证 provider_type 匹配
+            if token_data.provider_type != self.provider_type:
+                raise HTTPException(status_code=400, detail="绑定令牌与 Provider 不匹配")
+
+            # 从数据库获取用户
+            user = context.db.query(User).filter(User.id == token_data.user_id).first()
+            if not user or not user.is_active or user.is_deleted:
+                raise HTTPException(status_code=403, detail="用户不存在或已禁用")
+
+        assert user is not None
+        url = await OAuthService.build_bind_authorize_url(context.db, user, self.provider_type)
         return RedirectResponse(url=url, status_code=status.HTTP_302_FOUND)