fix: add dynamic route for custom OAuth provider callbacks (#2911)

Custom OAuth providers redirect to /oauth/{slug} after authorization,
but only hardcoded provider routes (github, discord, oidc, linuxdo)
existed in the frontend router, causing a 404 for custom providers.

web/src/App.jsx

@@ -18,7 +18,7 @@ For commercial licensing, please contact support@quantumnous.com
 */
 
 import React, { lazy, Suspense, useContext, useMemo } from 'react';
-import { Route, Routes, useLocation } from 'react-router-dom';
+import { Route, Routes, useLocation, useParams } from 'react-router-dom';
 import Loading from './components/common/ui/Loading';
 import User from './pages/User';
 import { AuthRedirect, PrivateRoute, AdminRoute } from './helpers';
@@ -56,6 +56,11 @@ const About = lazy(() => import('./pages/About'));
 const UserAgreement = lazy(() => import('./pages/UserAgreement'));
 const PrivacyPolicy = lazy(() => import('./pages/PrivacyPolicy'));
 
+function DynamicOAuth2Callback() {
+  const { provider } = useParams();
+  return <OAuth2Callback type={provider} />;
+}
+
 function App() {
   const location = useLocation();
   const [statusState] = useContext(StatusContext);
@@ -234,6 +239,14 @@ function App() {
             </Suspense>
           }
         />
+        <Route
+          path='/oauth/:provider'
+          element={
+            <Suspense fallback={<Loading></Loading>} key={location.pathname}>
+              <DynamicOAuth2Callback />
+            </Suspense>
+          }
+        />
         <Route
           path='/console/setting'
           element={