feat: add Auto Check MH Payment toggle with weekly schedule

Adds a toggle behind the Go button on the Payments page to automatically run the MH batch payment check on a user-selected day of week and hour. Default is off.

- Schema: added autoMhCheckEnabled, autoMhCheckDayOfWeek, autoMhCheckHour to User model
- Backend: new mhBatchPaymentService (shared logic), GET/PUT /auto-mh-check-setting routes, hourly cron job that fires on matching day+hour
- Frontend: toggle + day select (Mon–Sun) + time select (hourly) that persist immediately to DB

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/Backend/.env

@@ -5,6 +5,7 @@ CLOUDFLARE_HOST=
 FRONTEND_URLS=http://localhost:3000
 SELENIUM_AGENT_BASE_URL=http://localhost:5002
 JWT_SECRET = 'dentalsecret'
+LICENSE_SECRET=3aa4ab937e46c6863b9e3c2b591a595b31ea3af1060bf5e7961ad722a8b54f92
 DB_HOST=localhost
 DB_USER=postgres
 DB_PASSWORD=mypassword