Create a dev preview

[notangelmario]

Due to security reasons, deployment previews have been deleted and pull requests no longer get preview deployments.

The plan is to create a development preview hosted at dev.paquet.shop that will display changes in the dev branch. All deployments will need to be manually reviewed so they don't include any security holes.

The plan is to also use a custom icon and title for the web app.

Another plan would be to have all dev commits automatically deployed but to exclude the SUPABASE_SERVICE_KEY secret, so all features that require admin access will be disabled for security reasons.

[notangelmario]

Finally added a dev preview link but now more tasks arise:

• Add dynamically generated manifest
• Add custom icons for dev app
• Add custom name in manifest and title
• Add a specific env variable for development previews
• Add development preview disclaimer