- Add use cases section with 4 scenario cards (news, policy, business, fiction)
- Rewrite Thai home section text to be natural (not translated from Chinese)
- Add use case locale keys for th/en/zh
- Add CSS for use cases grid with hover effects
- Add isEnvAlive check on mount via /api/simulation/env-status
- Show warning banner when simulation env is not running
- Add alert() on survey failure for visibility
- Add envNotRunning translation key for th/en/zh
- Add locales/th.json with 629 translated keys
- Add Thai to languages.json with llmInstruction for report generation
- Backend auto-loads new locale files from locales/ directory