Progressive enhancement: provider form now works without JavaScript. Forms POST to ProvidersController (create/update), which handles validation and redirects with flash messages. With JS: LiveView phx-submit handles save, navigates with flash. Without JS: Form POSTs to controller, redirects with flash. Completes Task 3 of notification overhaul (admin forms migration). Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>