remove google and oauth login

frontend/src/app/core/services/auth.service.ts

@@ -50,23 +50,6 @@ export class AuthService {
     return !!this.getAccessToken();
   }
 
-  setSessionFromOAuth(accessToken: string, refreshToken: string): void {
-    localStorage.setItem(this.ACCESS_TOKEN_KEY, accessToken);
-    localStorage.setItem(this.REFRESH_TOKEN_KEY, refreshToken);
-    const payload = this.decodeToken(accessToken);
-    if (payload) {
-      const user: UserInfo = {
-        id: payload.sub,
-        email: payload.email,
-        name: payload.name,
-        avatarUrl: payload.avatarUrl || '',
-        provider: payload.provider || 'LOCAL',
-      };
-      localStorage.setItem(this.USER_KEY, JSON.stringify(user));
-      this.userSubject.next(user);
-    }
-  }
-
   clearSessionForLogout(): void {
     this.clearSession();
   }
@@ -90,12 +73,4 @@ export class AuthService {
     return data ? JSON.parse(data) : null;
   }
 
-  private decodeToken(token: string): any {
-    try {
-      const parts = token.split('.');
-      return JSON.parse(atob(parts[1]));
-    } catch {
-      return null;
-    }
-  }
 }