feat(caddy): integrate Bunny.net DNS and dynamic IP support

- Replace Bazarr with NZBGet in Caddyfile routes
- Add global DNS provider configuration for ACME DNS-01 challenges
- Implement dynamic DNS updater with Bunny.net provider
- Add comprehensive security headers and authentication
- Update documentation with new requirements and setup instructions
- Add .env.example, Dockerfile, cron jobs, and scripts
- Modify compose.yml to use local build and add environment variables

BREAKING CHANGE: Requires Bunny.net API key and updated Caddyfile configuration

cron/caddy-ddns-cert.cron

@@ -0,0 +1,3 @@
+# Crontab entry for Caddy Dynamic DNS and Certificate Sync
+# Run every 5 minutes to monitor IP changes
+*/5 * * * * /bin/bash -c '/app/scripts/ddns-cert-sync.sh >> /var/log/cron-caddy-ddns.log 2>&1'