4. File Structure

opwa/
├── opwa.php                          Main plugin file, constants, bootstrap
├── admin/
│   └── class-opwa-admin.php          All 9 admin tab views, save handlers, menu
├── assets/
│   ├── css/
│   │   └── opwa-admin-v2.css         Admin UI styles (Orravo design system)
│   └── js/
│       └── opwa-admin-v2.js          Admin JS: AJAX, media picker, charts, route builder
└── includes/
    ├── class-opwa-analytics.php      Summary / chart data, REST beacon/subscribe/unsubscribe
    ├── class-opwa-cli.php            WP-CLI commands
    ├── class-opwa-core.php           Plugin init, manifest/SW serving, AJAX handlers, icon gen
    ├── class-opwa-db.php             Database: tables, CRUD for subscribers/campaigns/analytics
    ├── class-opwa-push.php           VAPID keys, JWT, RFC 8188 encryption, send/send_to_all
    └── class-opwa-sw-builder.php     Dynamic service worker JS generator

Constants (defined in opwa.php):