Login-by-email feature and supporting infrastructure

[tomast1337]

This pull request implements email-based authentication and adds necessary supporting services and infrastructure.

Authentication & Email Features:

• Implement login-by-email using passport-magic-login
• Add email verification flow with handlebars templates
• Create MagicLinkEmailStrategy for email authentication
• Introduce MailService for SMTP email handling
• Add routes for email login and verification
• Add a username change option in the menu with the corresponding route

Infrastructure Updates:

• Add MinIO (self-hosted S3 alternative) services to docker-compose-dev.yml
• Add maildev service to docker-compose-dev.yml for local email testing
• Update EnvironmentVariables with new configs and validation

Technical Improvements:

• Refactor dependency injection to use useFactory and inject (Nest.js upgrade compatibility)
• Update login page UI to include email login option

Documentation Updates:

• CONTRIBUTING.md: The setup instructions have been updated to use docker-compose-dev.yml instead of docker-compose.yml. Additional environment variables and detailed setup instructions for both the backend and frontend have been added. New sections for running only the backend or frontend, populating the database with test data, and running tests have been included.

[tomast1337]

Just a reminder

TODO:

• If a new account has not been validated in some time, delete the account from the database (or only register the user when they 'return' with the token from the magic link)
• Add time limit (15 min-1 hour) to magic link login
• Add documentation in CONTRIBUTING.md for email and seed modules (e.g. seed routes only work in development mode)
• Format the email body a bit more nicely
• Local environment is not using mocked S3 URL (thumbnail URL is hardcoded to Backblaze in FileService, such that songs are always saved with this URL in the database)
• Rate-limit login by email route
• Front-end: redesign sign in page putting priority in magic link login
• Front-end: unify login form adding email field and 'Submit' button
• Add a notice on the front end about link expiration (e.g. A magic link has been sent to [email]! It will stay valid for one hour.)
• Remove auth/register backend route and use only auth/magic-link route; if the user doesn't exist, create it and use the email slug as username
• Add pencil in the user info popup so they can change their username
• Token cookie maxAge is provided in ms, not in seconds (verify this)

[tomast1337]

• Format the email body a bit more nicely

New account email

Verified and existing account email:

CSS in emails has many limitations. It can be improved somehow still.

[Bentroen]

Thanks for implementing these changes! The email template looks great now.

I'll still review the frontend and likely do some small changes, though I'm only able to do that after about the 22nd this month. Let me know when you're done with your changes :)

[tomast1337]

Currently, the rate limit is one login email per hour, this can be tweaked to a better-fitting value.

[Bentroen]

This PR is waiting on us setting up an email server to be merged. :)

[tomast1337]

This PR is waiting on us setting up an email server to be merged. :)

I feel it would be good to merge and maybe disable the email server-related feature until it's available.