Add complete infrastructure automation and documentation

- infrastructure/setup.sh: Master provisioning script for fresh Ubuntu servers
- infrastructure/docker-compose.yml: Production Docker Compose configuration
- infrastructure/.env.template: Environment variables template
- infrastructure/nginx/: Nginx configuration with security headers
- infrastructure/postfix/: Postfix + OpenDKIM email configuration
- infrastructure/README.md: Complete disaster recovery guide
- scripts/docfast-backup.sh: SQLite backup script with rotation

All services now fully reproducible with documented disaster recovery procedures.

infrastructure/.env.template

@@ -0,0 +1,27 @@
+# DocFast Environment Variables Template
+# Copy this to .env and fill in real values
+
+# Stripe Configuration (Production keys)
+STRIPE_SECRET_KEY=sk_live_FILL_IN_YOUR_STRIPE_SECRET_KEY
+STRIPE_WEBHOOK_SECRET=whsec_FILL_IN_YOUR_WEBHOOK_SECRET
+
+# Application Configuration
+BASE_URL=https://docfast.dev
+API_KEYS=FILL_IN_YOUR_API_KEYS_COMMA_SEPARATED
+PRO_KEYS=FILL_IN_YOUR_PRO_KEYS_COMMA_SEPARATED
+
+# Database Configuration
+DATABASE_PASSWORD=FILL_IN_SECURE_PASSWORD
+
+# Optional: Override defaults if needed
+# PORT=3100
+# NODE_ENV=production
+# SMTP_HOST=host.docker.internal
+# SMTP_PORT=25
+# DATABASE_HOST=172.17.0.1
+# DATABASE_PORT=5432
+# DATABASE_NAME=docfast
+# DATABASE_USER=docfast
+# POOL_SIZE=15
+# BROWSER_COUNT=1
+# PAGES_PER_BROWSER=15