feat: deprecate Pingvin file sharing service

- Remove Pingvin Docker Compose template and deployment tasks
- Remove files.thesatelliteoflove.com routing from Caddyfile
- Remove files subdomain from domain variables
- Stop and remove Pingvin containers from remote server
- Clean up /opt/stacks/pingvin directory

🤖 Generated with [Claude Code](https://claude.ai/code)

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

group_vars/all/domains.yml

@@ -21,7 +21,6 @@ subdomains:
   tasks: "tasks.{{ primary_domain }}"  # MMDL
   syncthing: "syncthing.{{ primary_domain }}"
   loclog: "loclog.{{ primary_domain }}"  # Dawarich
-  files: "files.{{ primary_domain }}"  # Pingvin file sharing
   social: "social.{{ primary_domain }}"  # GoToSocial
   post: "post.{{ primary_domain }}"  # Postiz
   home: "home.{{ primary_domain }}"  # Glance