Extract meeting point, share, import, and privacy modals from
folk-map-viewer.ts (2504→2147 lines) into standalone web components
that communicate via CustomEvent dispatch. Add OSM tile caching
(cache-first, LRU at 500), IndexedDB room state persistence for
offline location pinging, and auto-persist room state on every sync
update so last-known positions survive tab close.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>