fix: keep marker tooltip visible on touch devices when selected

On mobile/touch devices, Leaflet tooltips disappear immediately on tap
since there is no hover state. This makes the info bubble permanent for
the selected marker on touch devices so it stays readable.

Fixes #249

client/src/components/Map/MapView.tsx

@@ -422,6 +422,8 @@ export const MapView = memo(function MapView({
     })
   }, [])
 
+  const isTouchDevice = typeof window !== 'undefined' && ('ontouchstart' in window || navigator.maxTouchPoints > 0)
+
   const markers = useMemo(() => places.map((place) => {
     const isSelected = place.id === selectedPlaceId
     const cacheKey = place.google_place_id || place.osm_id || `${place.lat},${place.lng}`
@@ -444,6 +446,7 @@ export const MapView = memo(function MapView({
           offset={[0, 0]}
           opacity={1}
           className="map-tooltip"
+          permanent={isTouchDevice && isSelected}
         >
           <div style={{ fontFamily: "-apple-system, BlinkMacSystemFont, 'SF Pro Text', system-ui, sans-serif" }}>
             <div style={{ fontWeight: 600, fontSize: 12, color: 'var(--text-primary)', whiteSpace: 'nowrap' }}>
@@ -467,7 +470,7 @@ export const MapView = memo(function MapView({
         </Tooltip>
       </Marker>
     )
-  }), [places, selectedPlaceId, dayOrderMap, photoUrls, onMarkerClick])
+  }), [places, selectedPlaceId, dayOrderMap, photoUrls, onMarkerClick, isTouchDevice])
 
   return (
     <MapContainer