Refactor var generation and update service configs

- Refactor var generation scripts to use _rotate helper
- Update Glance service URLs to use configured ports
- Set static password hash for qBittorrent in Servarr config
- Update Caddy plugin hash
- Remove oauth_auto_login from Grafana config
- Add shared pwgen script for password generation

modules/nixos/services/observability/grafana/default.nix

@@ -36,7 +36,6 @@ in {
 
           auth = {
             disable_login_form = false;
-            oauth_auto_login = true;
           };
 
           "auth.basic".enable = false;