Add Bitwarden, setup script, remove redundant files, update disk requirements, and add LinuxServer preference

- Add Vaultwarden (Bitwarden) password manager to utilities.yml
  - Self-hosted password manager with web UI
  - SMTP configuration for email notifications
  - Admin token for management
  - Access at bitwarden.${DOMAIN}
  - Protected by Authelia SSO

- Create automated first-run setup script (scripts/setup-homelab.sh)
  - Installs Docker Engine and Compose V2
  - Configures user groups (sudo, docker)
  - Enables SSH for remote management
  - Detects NVIDIA GPU and provides manual driver installation instructions
  - Creates directory structure and Docker networks
  - Comprehensive instructions for post-setup deployment

- Remove redundant compose files (now in core.yml)
  - Deleted authelia.yml, duckdns.yml, gluetun.yml, traefik.yml
  - All services consolidated into unified core.yml stack
  - Eliminates confusion and duplication

- Update disk space requirements across documentation
  - Changed from "100GB+ system, 1TB+ media" to:
  - "120GB+ system drive (NVMe or SSD highly recommended)"
  - "2TB+ for media & additional disks for services like Nextcloud"
  - Updated in README.md and getting-started.md

- Add preference for LinuxServer.io images
  - Updated copilot-instructions.md
  - LinuxServer images support PUID/PGID for proper file permissions
  - Preference noted in consistency guidelines

- Update core stack documentation
  - Emphasize unified core.yml deployment
  - Add both deployment methods (cd to directory vs full path)
  - Update getting-started.md with correct deployment steps
  - Note removal of separate stack files

- Add Bitwarden environment variables to .env.example
  - BITWARDEN_ADMIN_TOKEN, SIGNUPS_ALLOWED, INVITATIONS_ALLOWED
  - SMTP configuration for email notifications
  - Generation instructions included

- Update services-reference.md
  - Add Vaultwarden to utilities section (now 7 services)
  - Update service count and access URLs

All documentation now consistent with unified core stack approach and includes all requested features.

Co-authored-by: kelinfoxy <67766943+kelinfoxy@users.noreply.github.com>

.env.example

@@ -174,6 +174,17 @@ JUPYTER_TOKEN=changeme
 # Pi-hole
 PIHOLE_PASSWORD=changeme
 
+# Bitwarden (Vaultwarden) Password Manager
+# Admin token: openssl rand -base64 48
+BITWARDEN_ADMIN_TOKEN=changeme-bitwarden-admin-token
+BITWARDEN_SIGNUPS_ALLOWED=true  # Set to false after creating accounts
+BITWARDEN_INVITATIONS_ALLOWED=true
+SMTP_HOST=smtp.gmail.com
+SMTP_FROM=bitwarden@yourdomain.com
+SMTP_PORT=587
+SMTP_SECURITY=starttls
+# SMTP_USERNAME and SMTP_PASSWORD defined above
+
 # Watchtower Notifications (optional)
 # WATCHTOWER_NOTIFICATION_URL=