��## Description

This PR implements two major security and authentication flows in the backend:

1. Forgot / Reset Password Flow (BE-12)
2. Google OAuth 2.0 SSO (BE-14)

Password Reset Flow

• Rebuilt the PasswordResetToken entity with relations to User.
• Added /auth/forgot-password endpoint: securely generates a random token, hashes it with bcrypt, and saves it in the database with a 1-hour expiration timestamp.
• Added /auth/reset-password endpoint: validates the raw token against the stored hash, validates expiry, updates the user's password, and marks the token as used.

Google SSO

• Integrated passport-google-oauth20 with a new GoogleStrategy.
• Added /auth/google and /auth/google/callback endpoints.
• Updated User entity to include a nullable googleId field. Existing users are automatically linked to their Google account if the email matches.

Notes on Dependencies

• Re-created basic scaffolding for User and MailService since the opsce module was wiped out in a recent commit on main.

Related Issues

Closes #885
Closes #887

Type of Change

• New feature (non-breaking change which adds functionality)
• Security enhancement

Verification

• Validated that
  pm run build succeeds locally.
• Verified that sensitive variables (GOOGLE_CLIENT_ID, FRONTEND_URL) are correctly mapped via ConfigService.