v2.1.0 — Real-time collaboration, performance & security overhaul

Real-Time Collaboration (WebSocket):
- WebSocket server with JWT auth and trip-based rooms
- Live sync for all CRUD operations (places, assignments, days, notes, budget, packing, reservations, files)
- Socket-based exclusion to prevent duplicate updates
- Auto-reconnect with exponential backoff
- Assignment move sync between days

Performance:
- 16 database indexes on all foreign key columns
- N+1 query fix in places, assignments and days endpoints
- Marker clustering (react-leaflet-cluster) with configurable radius
- List virtualization (react-window) for places sidebar
- useMemo for filtered places
- SQLite WAL mode + busy_timeout for concurrent writes
- Weather API: server-side cache (1h forecast, 15min current) + client sessionStorage
- Google Places photos: persisted to DB after first fetch
- Google Details: 3-tier cache (memory → sessionStorage → API)

Security:
- CORS auto-configuration (production: same-origin, dev: open)
- API keys removed from /auth/me response
- Admin-only endpoint for reading API keys
- Path traversal prevention in cover image deletion
- JWT secret persisted to file (survives restarts)
- Avatar upload file extension whitelist
- API key fallback: normal users use admin's key without exposure
- Case-insensitive email login

Dark Mode:
- Fixed hardcoded colors across PackingList, Budget, ReservationModal, ReservationsPanel
- Mobile map buttons and sidebar sheets respect dark mode
- Cluster markers always dark

UI/UX:
- Redesigned login page with animated planes, stars and feature cards
- Admin: create user functionality with CustomSelect
- Mobile: day-picker popup for assigning places to days
- Mobile: touch-friendly reorder buttons (32px targets)
- Mobile: responsive text (shorter labels on small screens)
- Packing list: index-based category colors
- i18n: translated date picker placeholder, fixed German labels
- Default map tile: CartoDB Light

client/src/components/Weather/WeatherWidget.jsx

@@ -20,7 +20,17 @@ function WeatherIcon({ main, size = 13 }) {
   return <Icon size={size} strokeWidth={1.8} />
 }
 
-const weatherCache = {}
+function getWeatherCache(key) {
+  try {
+    const raw = sessionStorage.getItem(key)
+    if (raw === null) return undefined
+    return JSON.parse(raw)
+  } catch { return undefined }
+}
+
+function setWeatherCache(key, value) {
+  try { sessionStorage.setItem(key, JSON.stringify(value)) } catch {}
+}
 
 export default function WeatherWidget({ lat, lng, date, compact = false }) {
   const [weather, setWeather] = useState(null)
@@ -30,24 +40,27 @@ export default function WeatherWidget({ lat, lng, date, compact = false }) {
 
   useEffect(() => {
     if (!lat || !lng || !date) return
-    const cacheKey = `${lat},${lng},${date}`
-    if (weatherCache[cacheKey] !== undefined) {
-      if (weatherCache[cacheKey] === null) setFailed(true)
-      else setWeather(weatherCache[cacheKey])
+    const rLat = Math.round(lat * 100) / 100
+    const rLng = Math.round(lng * 100) / 100
+    const cacheKey = `weather_${rLat}_${rLng}_${date}`
+    const cached = getWeatherCache(cacheKey)
+    if (cached !== undefined) {
+      if (cached === null) setFailed(true)
+      else setWeather(cached)
       return
     }
     setLoading(true)
     weatherApi.get(lat, lng, date)
       .then(data => {
         if (data.error || data.temp === undefined) {
-          weatherCache[cacheKey] = null
+          setWeatherCache(cacheKey, null)
           setFailed(true)
         } else {
-          weatherCache[cacheKey] = data
+          setWeatherCache(cacheKey, data)
           setWeather(data)
         }
       })
-      .catch(() => { weatherCache[cacheKey] = null; setFailed(true) })
+      .catch(() => { setWeatherCache(cacheKey, null); setFailed(true) })
       .finally(() => setLoading(false))
   }, [lat, lng, date])