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.example

@@ -13,11 +13,16 @@ ADMIN_URL=http://localhost:3005
 FRONTEND_URL=http://localhost:3005
 BACKEND_URL=http://localhost:3001
 
-# Database Configuration (SQLite for development)
-DATABASE_CLIENT=sqlite3
-DATABASE_PATH=./data/photo_sharing.db
+# Database Configuration (PostgreSQL for development)
+DATABASE_CLIENT=pg
+DB_HOST=db
+DB_PORT=5432
+DB_NAME=picpeak
+DB_USER=picpeak
+DB_PASSWORD=picpeak
 
-# Email Configuration (Mailhog for development)
+# Email Configuration
+# For development with docker-compose.dev.yml:
 # Access Mailhog UI at: http://localhost:8025
 SMTP_HOST=mailhog
 SMTP_PORT=1025
@@ -26,6 +31,14 @@ SMTP_USER=
 SMTP_PASS=
 EMAIL_FROM=noreply@localhost
 
+# For development without Docker, use real SMTP:
+# SMTP_HOST=smtp.gmail.com
+# SMTP_PORT=587
+# SMTP_SECURE=false
+# SMTP_USER=your-email@gmail.com
+# SMTP_PASS=your-app-password
+# EMAIL_FROM=PicPeak Dev <your-email@gmail.com>
+
 # Backend Port Configuration
 PORT=3001
 
@@ -40,8 +53,13 @@ PORT=3001
 NODE_ENV=development
 LOG_LEVEL=debug
 
+# Storage Settings (optional)
+DEFAULT_EXPIRATION_DAYS=30
+WARNING_DAYS_BEFORE_EXPIRY=7
+
 # Admin Setup Notes:
-# 1. Run 'npm run migrate' in backend folder
-# 2. Admin credentials will be auto-generated
-# 3. Check ADMIN_CREDENTIALS.txt for login details
-# 4. Change password on first login (required)
+# 1. Run 'docker-compose -f docker-compose.dev.yml up -d'
+# 2. Run 'docker-compose -f docker-compose.dev.yml exec backend npm run migrate'
+# 3. Admin credentials will be auto-generated
+# 4. Check backend/ADMIN_CREDENTIALS.txt for login details
+# 5. Change password on first login (required)