Leaflet accesses `window` on import, crashing during SSR. Renamed
RouteMapThumbnail to .client.tsx so React Router excludes it from
the server bundle entirely. Updated all lazy() imports to match.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
- Route/activity list pages: map thumbnails with route drawn on OSM tiles
- Route/activity detail pages: interactive Leaflet map with zoom controls
- Server: expose GeoJSON from PostGIS via ST_AsGeoJSON (simplified for lists)
- RouteMapThumbnail component: shared, supports thumbnail and interactive modes
- Placeholder shown for routes/activities without geometry
- Archive journal-route-previews change, sync specs
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
