Fix JSON parsing errors when server returns non-JSON responses:
- Check response.ok before calling response.json()
- Add fallback error messages using status text
- Apply fix to all fetch calls across 12 components
This prevents 'JSON.parse: unexpected character' errors when
server returns HTML error pages or other non-JSON responses.
- Fixed unused variables in unit tests (elo.test.ts, permissions.test.ts)
- Fixed unused variables in E2E tests (account-acceptance.test.ts, elo-ratings.test.ts, epic1-auth-registration.test.ts, global.setup.ts)
- Fixed 'any' type usage in EditTournamentForm.test.tsx and auth-simple.test.ts
- Fixed unescaped quotes and apostrophes in React components
- Fixed TypeScript type errors in Navigation.tsx, test-api/page.tsx, and matches/upload/page.tsx
- Fixed missing useEffect dependency in tournaments/[id]/entry/page.tsx
- Updated eslint config to exclude test-api directory
- All tests now pass linting and build successfully
david