feat: implement OAuth 2.0 / OpenID Connect support

- Added OAuth configuration management in the admin panel.
- Implemented OAuth authorization flow with PKCE for enhanced security.
- Created routes for handling OAuth provider discovery, authorization, and callback.
- Integrated OAuth login and registration options in the frontend.
- Updated UI components to support OAuth login and registration.
- Added internationalization strings for OAuth-related messages.
- Implemented encryption for client secrets and secure state management.
- Added error handling and user feedback for OAuth processes.

src/contexts/AuthContext.jsx

@@ -50,12 +50,24 @@ export function AuthProvider({ children }) {
     setUser(null);
   }, []);
 
+  const loginWithOAuth = useCallback(async (token) => {
+    localStorage.setItem('token', token);
+    try {
+      const res = await api.get('/auth/me');
+      setUser(res.data.user);
+      return res.data.user;
+    } catch (err) {
+      localStorage.removeItem('token');
+      throw err;
+    }
+  }, []);
+
   const updateUser = useCallback((updatedUser) => {
     setUser(updatedUser);
   }, []);
 
   return (
-    <AuthContext.Provider value={{ user, loading, login, register, logout, updateUser }}>
+    <AuthContext.Provider value={{ user, loading, login, register, logout, loginWithOAuth, updateUser }}>
       {children}
     </AuthContext.Provider>
   );