refactor: complete configuration cleanup and consistency fixes

- Create docker-compose.dev.yml with Mailhog for development email testing
- Standardize all configurations to use PORT=3001 for backend
- Fix database service naming (postgres → db) across all files
- Add missing BACKEND_URL environment variable to all configs
- Update .env examples to match actual Docker setup requirements
- Remove orphaned postgres-init directory (Umami handles its own DB)
- Update README roadmap: mark gallery feedback as implemented, add multi-admin support
- Update deployment guide with development setup instructions
- Fix frontend Dockerfile.dev for proper hot-reload development
- Remove unused files (wedding-photos.db, frontend/README.md)

This ensures all configuration files are consistent and aligned with the deployment guide.

.env.production.example

@@ -20,7 +20,7 @@ ADMIN_URL=https://your-domain.com
 
 # PostgreSQL Configuration (Recommended for production)
 DATABASE_CLIENT=pg
-DB_HOST=postgres  # or your database host
+DB_HOST=db  # Use 'db' for Docker Compose, or external host
 DB_PORT=5432
 DB_NAME=picpeak
 DB_USER=picpeak
@@ -61,7 +61,7 @@ EMAIL_FROM=PicPeak <[email protected]>
 # Primary config via Admin UI > Settings > Analytics
 # UMAMI_URL=https://analytics.your-domain.com
 # UMAMI_WEBSITE_ID=your-website-id
-# UMAMI_HASH_SALT=your-hash-salt
+# UMAMI_HASH_SALT=your-hash-salt  # Required if using Umami
 
 # Frontend Analytics (Optional - Fallback values)
 # VITE_UMAMI_URL=https://analytics.your-domain.com
@@ -76,6 +76,13 @@ NODE_ENV=production
 PORT=3001
 LOG_LEVEL=info
 
+# Backend URL (if different from frontend)
+# BACKEND_URL=https://api.your-domain.com
+
+# Storage Settings
+DEFAULT_EXPIRATION_DAYS=30
+WARNING_DAYS_BEFORE_EXPIRY=7
+
 # Security Settings (Defaults are secure)
 BCRYPT_ROUNDS=12
 SESSION_TIMEOUT_MINUTES=60