- Add async initialization with 6 phases: scanning_assets, loading_map,
initializing_sects, generating_avatars, checking_llm, generating_initial_events
- Add /api/init-status endpoint for frontend polling
- Add /api/control/reinit endpoint for error recovery
- Add LoadingOverlay.vue component with:
- Progress ring with gradient
- Phase text in xianxia style (rotating messages for LLM phase)
- Tips that rotate every 5 seconds
- Time-based background transparency (fades to 80% over 20s)
- Backdrop blur effect
- Error state with retry button
- Preload map and avatars during LLM initialization for smoother UX
- Add comprehensive tests for init status API
