feat(database): add migration and sync-db scripts to deployment process

- Introduced a new npm script for database migrations in package.json.
- Updated update-backend.sh to execute migrations and conditionally run legacy sync-db based on environment variable.
- Enhanced syncDatabase.js to skip initialization routines if APP_INIT_ON_START is not set, promoting best practices for schema changes during deployment.

backend/config/sequelize-cli.cjs

@@ -0,0 +1,32 @@
+const path = require('path');
+const dotenv = require('dotenv');
+
+const envPath = process.env.SEQUELIZE_ENV_FILE
+  ? path.resolve(process.cwd(), process.env.SEQUELIZE_ENV_FILE)
+  : path.resolve(process.cwd(), '.env');
+
+dotenv.config({ path: envPath });
+
+const dialectOptions = {};
+if (process.env.DB_SSL === '1' || process.env.PGSSLMODE === 'require') {
+  dialectOptions.ssl = process.env.DB_SSL_REJECT_UNAUTHORIZED === '0'
+    ? { rejectUnauthorized: false }
+    : true;
+}
+
+const shared = {
+  username: process.env.DB_USER,
+  password: process.env.DB_PASS || '',
+  database: process.env.DB_NAME,
+  host: process.env.DB_HOST || '127.0.0.1',
+  port: Number.parseInt(process.env.DB_PORT || '5432', 10),
+  dialect: 'postgres',
+  logging: false,
+  dialectOptions
+};
+
+module.exports = {
+  development: shared,
+  test: shared,
+  production: shared
+};