Implement Email/Password Authentication with Email Verification for Manga Reader

[duckie-ai-helper]

• Extend the existing Manga Reader sign-in functionality to incorporate email/password sign-in along with the existing Google sign-in.
• Implement a sign-up feature allowing users to register using their email and a password.
• An email verification step should be included during the sign-up phase, and user access will be blocked until email verification is completed.
• Incorporate a 'forgot password' feature that sends a password reset link to the user's registered email.
• Ensure that the backend processes both Google and email/password sign-ins correctly.
• There should not be any constraints on password complexity during registration.
• The system should be non-discriminative, offering both Google and email/password sign-in methods for users to select their preferred login method.