- add Open Graph and Twitter card metadata to root app layout, using NEXT_PUBLIC_SITE_URL for absolute canonical URLs and social image paths
- introduce NEXT_PUBLIC_SITE_URL environment variable to configure the app's public base URL
- add environment variable definitions to .env.local.example and coolify.env
- create scripts/make-og.py to generate 1200x630 pixel social share images
- add public/og.png as the default social share asset
- add .shrink CSS utility class for flex layout control
- update app build manifests and route entries for new application pages
