feat(journey): combined map+timeline view on mobile (Polarsteps-style)

Merge the separate Timeline and Map tabs into a single fullscreen
combined view on mobile (<1024px). A Leaflet map fills the background
while a horizontal snap-scroll carousel of entry cards sits at the
bottom. Scrolling the carousel auto-focuses the corresponding map
marker; tapping a marker scrolls to the card. Tapping a card opens
a new fullscreen entry view with edit/delete actions.

- New: MobileMapTimeline, MobileEntryCard, MobileEntryView components
- New: useIsMobile hook (matchMedia < 1024px)
- JourneyMap: fullScreen + paddingBottom props, focusMarker guard
- Desktop layout completely unchanged
- Public share page gets the same combined view (read-only)
- Fix: entry editor now portaled to body (iOS stacking context)
- Fix: pros/cons dark mode input backgrounds
- Fix: mood button borders in dark mode
- Fix: location icon color (neutral instead of green/indigo)

client/src/i18n/translations/en.ts

@@ -1958,6 +1958,7 @@ const en: Record<string, string | { name: string; category: string }[]> = {
   'journey.detail.noEntriesHint': 'Add a trip to get started with skeleton entries',
   'journey.detail.noPhotos': 'No photos yet',
   'journey.detail.noPhotosHint': 'Upload photos to entries or browse your Immich/Synology library',
+  'journey.detail.journeyTab': 'Journey',
   'journey.detail.journeyStats': 'Journey Stats',
   'journey.detail.syncedTrips': 'Synced Trips',
   'journey.detail.noTripsLinked': 'No trips linked yet',