chore: consolidate and update deployment documentation

- Remove completed PRODUCTION_TODO_LIST.md
- Consolidate deployment guides: keep comprehensive PRODUCTION_DEPLOYMENT_GUIDE.md, remove redundant PRODUCTION_DEPLOYMENT.md
- Update all .env.example files to reflect current system:
  - Remove deprecated ADMIN_EMAIL/ADMIN_PASSWORD (now auto-generated)
  - Add proper documentation for all environment variables
  - Clarify that Umami config is optional (primary via Admin UI)
  - Add realistic examples for SMTP providers
  - Update ports to match actual defaults (3001)
- Update PRODUCTION_DEPLOYMENT_GUIDE.md:
  - Document auto-generated admin credentials process
  - Add Traefik configuration section
  - Update security checklist with current features
  - Fix outdated environment variables
  - Add nginx proxy configuration details

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

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

backend/.env.example

@@ -3,39 +3,56 @@
 
 # Application
 NODE_ENV=production
-PORT=3000
+PORT=3001
 
 # Security
-JWT_SECRET=your-very-secure-jwt-secret-at-least-32-characters-long
+# Generate with: openssl rand -base64 32
+JWT_SECRET=your-very-secure-jwt-secret-at-least-32-characters-long-example123456
 
-# URLs
-ADMIN_URL=https://yourdomain.com
-FRONTEND_URL=https://yourdomain.com
+# URLs (adjust for your domain)
+ADMIN_URL=https://photos.example.com
+FRONTEND_URL=https://photos.example.com
 
 # Database Configuration
 DATABASE_CLIENT=pg
-DB_HOST=db
+DB_HOST=localhost
 DB_PORT=5432
 DB_USER=picpeak
-DB_PASSWORD=your-secure-database-password
+DB_PASSWORD=your-secure-database-password-change-this
 DB_NAME=picpeak
 
-# Email Configuration
-SMTP_HOST=smtp.example.com
+# Email Configuration (Examples for common providers)
+# Gmail example:
+# SMTP_HOST=smtp.gmail.com
+# SMTP_PORT=587
+# SMTP_SECURE=false
+# SMTP_USER=your-email@gmail.com
+# SMTP_PASS=your-app-specific-password
+
+# SendGrid example:
+SMTP_HOST=smtp.sendgrid.net
 SMTP_PORT=587
 SMTP_SECURE=false
-SMTP_USER=your-smtp-username
-SMTP_PASS=your-smtp-password
-EMAIL_FROM=noreply@yourdomain.com
+SMTP_USER=apikey
+SMTP_PASS=your-sendgrid-api-key
+EMAIL_FROM=noreply@example.com
 
-# Storage Paths (Docker)
+# Storage Paths
+# Docker deployment:
 STORAGE_PATH=/app/storage
 EVENTS_PATH=/app/storage/events
 ARCHIVE_PATH=/app/storage/events/archived
 
-# Analytics (Optional)
-UMAMI_URL=https://analytics.yourdomain.com
-UMAMI_WEBSITE_ID=your-website-id
+# Local development:
+# STORAGE_PATH=./storage
+# EVENTS_PATH=./storage/events
+# ARCHIVE_PATH=./storage/events/archived
+
+# Analytics Backend Configuration (OPTIONAL)
+# Used for server-side tracking only
+# Primary configuration should be done through Admin UI > Settings > Analytics
+# UMAMI_URL=https://analytics.example.com
+# UMAMI_WEBSITE_ID=b4d3c2a1-5678-90ab-cdef-1234567890ab
 
 # Logging
 LOG_LEVEL=info