feat: add git.skudak.com Gitea instance and skudak domain migrations

Gitea Skudak (git.skudak.com):
- New Gitea instance with PostgreSQL in podman pod under git user
- SSH access via Gitea's built-in SSH server on port 2222
- Registration restricted to @skudak.com emails with email confirmation
- SMTP configured for email delivery

Domain migrations:
- wiki.skudakrennsport.com → wiki.skudak.com (302 redirect)
- cloud.skudakrennsport.com + cloud.skudak.com (dual-domain serving)
- BookStack APP_URL updated to wiki.skudak.com
- Nextcloud trusted_domains updated for cloud.skudak.com

Infrastructure:
- SELinux context for git user container storage (container_file_t)
- Firewall rule for port 2222/tcp (Gitea Skudak SSH)
- Caddy reverse proxy for git.skudak.com

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

ansible/roles/git/defaults/main.yml

@@ -6,3 +6,7 @@ git_home: "/srv/{{ git_user }}"
 gitea_debyl_server_name: git.debyl.io
 gitea_image: docker.gitea.com/gitea:1.25.2
 gitea_db_image: docker.io/library/postgres:14-alpine
+
+# Skudak Gitea configuration
+gitea_skudak_server_name: git.skudak.com
+gitea_skudak_ssh_port: 2222