feat: add Digital Ocean deployment configuration

- Create docker-compose.digitalocean.yml for registry-based deployment
- Add .env.digitalocean.example template for cloud deployment
- Add comprehensive DIGITAL_OCEAN_DEPLOYMENT.md guide
- Configure image pulling from Gitea registry
- Include SSL setup with Caddy/Traefik
- Add backup, monitoring, and security instructions

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

.env.digitalocean.example

@@ -0,0 +1,46 @@
+# ==========================================
+# VIP Coordinator - Digital Ocean Environment
+# ==========================================
+# Copy this file to .env.digitalocean and fill in your values
+# Then deploy with: docker-compose -f docker-compose.digitalocean.yml --env-file .env.digitalocean up -d
+
+# ==========================================
+# Gitea Registry Configuration
+# ==========================================
+# Your local Gitea server (accessible from Digital Ocean)
+# If Gitea is on your LAN, you'll need to expose it or use a VPN
+GITEA_REGISTRY=YOUR_PUBLIC_GITEA_URL:3000
+IMAGE_TAG=latest
+
+# ==========================================
+# Database Configuration
+# ==========================================
+POSTGRES_DB=vip_coordinator
+POSTGRES_USER=vip_user
+POSTGRES_PASSWORD=CHANGE_ME_TO_STRONG_PASSWORD_12345
+
+# ==========================================
+# Auth0 Configuration
+# ==========================================
+# Get these from your Auth0 dashboard
+# IMPORTANT: Update Auth0 callbacks to use your production domain
+AUTH0_DOMAIN=dev-s855cy3bvjjbkljt.us.auth0.com
+AUTH0_AUDIENCE=https://vip-coordinator-api
+AUTH0_ISSUER=https://dev-s855cy3bvjjbkljt.us.auth0.com/
+AUTH0_CLIENT_ID=JXEVOIfS5eYCkeKbbCWIkBYIvjqdSP5d
+
+# ==========================================
+# Frontend Configuration
+# ==========================================
+# Port 80 for HTTP (will be behind reverse proxy for HTTPS)
+FRONTEND_PORT=80
+
+# ==========================================
+# Optional: External APIs
+# ==========================================
+AVIATIONSTACK_API_KEY=
+
+# ==========================================
+# Optional: Database Seeding
+# ==========================================
+RUN_SEED=false