Implement zero-downtime deployments

[dsebastien]

Currently, deployments make the hosted version of Knowii unavailable for a while.
Once we grow enough, this will become really problematic.

We should use Laravel Envoyer ($10/month): https://envoyer.io/

Steps:

• Subscribe to Envoyer
• Link Envoyer and Forge accounts
• Import the Forge Server into Envoyer: https://forge.laravel.com/docs/sites/envoyer.html#migrating-an-existing-site-to-envoyer
• Sync the environment file
• Configure deployment hooks
• Configure Health Check URL in Envoyer project settings and point it to /up (available by default with Laravel 11+)

On the server, the cloned project will be moved to releases//, and a "current" symlink will be created, pointing to the latest release, and each release will include the .env file

Deployment hooks we need:

1. Build front-end (npm install and npm run build)
2. Run Laravel Caches: php artisan route:cache, config:cache, view:cache
   ...

Examples: