Add mail verification and use .env insteads of environment in compose

.env.example

@@ -12,9 +12,24 @@ JWT_SECRET=your-super-secret-jwt-key-change-this
 # DATABASE_URL=postgres://user:password@localhost:5432/redlight
 DATABASE_URL=
 
+POSTGRES_USER=redlight
+POSTGRES_PASSWORD=redlight
+POSTGRES_DB=redlight
+
 # SQLite file path (only used when DATABASE_URL is not set)
 # SQLITE_PATH=./redlight.db
 
 # Default Admin Account (created on first run)
 ADMIN_EMAIL=admin@example.com
 ADMIN_PASSWORD=admin123
+
+# SMTP Configuration (for email verification)
+# If not set, registration works without email verification
+SMTP_HOST=smtp.example.com
+SMTP_PORT=587
+SMTP_USER=noreply@example.com
+SMTP_PASS=your-smtp-password
+SMTP_FROM=noreply@example.com
+
+# App URL (used for verification links, auto-detected if not set)
+# APP_URL=https://your-domain.com