- Fix login-form.test.tsx: replace undefined 'form' variable with proper element check
- Fix event-list.test.tsx: use getAllByRole('combobox') for select elements without labels
- Fix event-list.test.tsx: match actual error message text instead of generic message
- Fix dashboard.test.tsx: match actual error message and support different number formatting
- Create dashboard.test.tsx with 14 test cases
- Tests for organizer dashboard (loading, data display, quick actions)
- Tests for participant dashboard (stats, registrations)
- Negative tests for API failures and null data