feat: booking UX improvements — waiting list, card focus, sort order

- Auto-note "Лист ожидания" for registrations when class is full
- Waiting list triggers on confirmed count (not total registrations)
- Card highlight + scroll after status change
- Hover effect on booking cards
- Freshly changed cards appear first in their status group
- Polling no longer remounts tabs (fixes page jump on approve)
- Fix MasterClassesData missing waitingListText type
- Add Turbopack troubleshooting docs to CLAUDE.md

CLAUDE.md

@@ -158,6 +158,15 @@ src/
 - Migrations run automatically on server start via `runMigrations()` and are tracked in the `_migrations` table
 - Use `CREATE TABLE IF NOT EXISTS` and column-existence checks (`PRAGMA table_info`) for safety
 
+## Turbopack / Dev Server Troubleshooting
+If the dev server hangs on "Compiling..." or shows a white page:
+1. Kill all node processes: `taskkill /F /IM node.exe`
+2. Remove stale lock: `rm -f .next/dev/lock`
+3. Clear cache: `rm -rf .next node_modules/.cache`
+4. Restart: `npm run dev`
+- This often happens after shutting down the PC without stopping the server first
+- Always stop the dev server (Ctrl+C) before shutting down
+
 ## Git
 - Remote: Gitea at `git.dolgolyov-family.by`
 - User: diana.dolgolyova