Switch mobile app to dark theme and fix calendar filtering

Switch mobile app to dark theme and fix calendar filtering

- Default to dark theme in mobile app, matching web app style
- Filter native calendar events by location to exclude empty ones
- Add batch edit panel for destinations on web calendar
- Add edit support to AddEventModal
- Update notification trigger input type export

apps/mobile/src/screens/SettingsScreen.tsx

@@ -29,6 +29,7 @@ export function SettingsScreen({ navigation: _navigation }: ScreenProps) {
   const [query, setQuery] = useState('');
   const [results, setResults] = useState<Station[]>([]);
   const [searching, setSearching] = useState(false);
+  const [searchError, setSearchError] = useState<string | null>(null);
   const [notifSettings, setNotifSettings] = useState<ReminderSettings>({
     bufferMinutes: 30,
     enabled: true,
@@ -41,11 +42,11 @@ export function SettingsScreen({ navigation: _navigation }: ScreenProps) {
   const searchTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
 
   const colors = dark ? {
-    background: '#1c1c1e',
-    card: '#2c2c2e',
-    text: '#f2f2f2',
-    subtext: '#aeaeb2',
-    accent: '#0a84ff',
+    background: '#090816',
+    card: '#17112A',
+    text: '#F4F1EA',
+    subtext: 'rgba(244,241,234,0.5)',
+    accent: '#8B5CF6',
     border: '#38383a',
     success: '#30d158',
   } : {
@@ -53,7 +54,7 @@ export function SettingsScreen({ navigation: _navigation }: ScreenProps) {
     card: '#ffffff',
     text: '#1c1c1e',
     subtext: '#8e8e93',
-    accent: '#007AFF',
+    accent: '#B23CFF',
     border: '#e5e5ea',
     success: '#34C759',
   };
@@ -72,14 +73,18 @@ export function SettingsScreen({ navigation: _navigation }: ScreenProps) {
   const searchStation = useCallback(async (q: string) => {
     if (q.trim().length < 2) {
       setResults([]);
+      setSearchError(null);
       return;
     }
     setSearching(true);
+    setSearchError(null);
     try {
       const stations = await api.searchStation(q.trim());
       setResults(stations);
+      if (stations.length === 0) setSearchError('Keine Stationen gefunden.');
     } catch {
       setResults([]);
+      setSearchError('API nicht erreichbar. Läuft der Server auf deinem Gerät? Überprüfe EXPO_PUBLIC_API_BASE_URL in .env.');
     } finally {
       setSearching(false);
     }
@@ -87,6 +92,7 @@ export function SettingsScreen({ navigation: _navigation }: ScreenProps) {
 
   const onQueryChange = (text: string) => {
     setQuery(text);
+    setSearchError(null);
     // Proper debounce using useRef — no `any`
     if (searchTimerRef.current) clearTimeout(searchTimerRef.current);
     searchTimerRef.current = setTimeout(() => searchStation(text), 400);
@@ -121,8 +127,10 @@ export function SettingsScreen({ navigation: _navigation }: ScreenProps) {
 
       // Try the WienerLinien nearby-stops proxy first
       let stops: Awaited<ReturnType<typeof api.findNearbyStops>> | null = null;
+      let apiReachable = false;
       try {
         stops = await api.findNearbyStops(userLat, userLng, 2000);
+        apiReachable = true;
       } catch {
         // API unavailable, will fall back to HAFAS LocMatch below
       }
@@ -146,15 +154,28 @@ export function SettingsScreen({ navigation: _navigation }: ScreenProps) {
       }
 
       // Fallback: use HAFAS LocMatch directly (same pattern as the web app)
-      const nearestStation = await api.findNearestStationByCoords(userLat, userLng);
-      if (!nearestStation) {
-        Alert.alert('Keine Station gefunden', 'Kein ÖPNV-Halt in der Nähe gefunden.');
+      try {
+        const nearestStation = await api.findNearestStationByCoords(userLat, userLng);
+        if (!nearestStation) {
+          Alert.alert('Keine Station gefunden', 'Kein ÖPNV-Halt in der Nähe gefunden.');
+          return;
+        }
+        await selectStation(nearestStation);
         return;
+      } catch {
+        // API not reachable
       }
 
-      await selectStation(nearestStation);
+      if (!apiReachable) {
+        Alert.alert(
+          'API nicht erreichbar',
+          'Der Server konnte nicht erreicht werden. Stelle sicher, dass EXPO_PUBLIC_API_BASE_URL in der .env-Datei auf die LAN-IP deines Entwicklungsrechners zeigt (z. B. http://192.168.1.x:3000) und nicht auf localhost.'
+        );
+      } else {
+        Alert.alert('Keine Station gefunden', 'Kein ÖPNV-Halt in der Nähe gefunden.');
+      }
     } catch (_err) {
-      Alert.alert('Fehler', 'Standort konnte nicht ermittelt werden.');
+      Alert.alert('Fehler', 'Standortermittlung fehlgeschlagen. Bitte überprüfe die Berechtigungen in den Systemeinstellungen.');
     }
   };
 
@@ -232,6 +253,9 @@ export function SettingsScreen({ navigation: _navigation }: ScreenProps) {
           accessibilityLabel="Station suchen"
         />
         {searching && <ActivityIndicator style={{ marginVertical: 8 }} color={colors.accent} />}
+        {searchError && (
+          <Text style={[styles.errorText, { color: '#ff453a' }]}>{searchError}</Text>
+        )}
         {origin && (
           <Text style={[styles.currentStation, { color: colors.success }]}>Aktuell: {origin.name}</Text>
         )}
@@ -344,6 +368,7 @@ const styles = StyleSheet.create({
   },
   locBtnText: { fontSize: 15, fontWeight: '500' },
   locStatus: { fontSize: 12, marginTop: 6 },
+  errorText: { fontSize: 13, marginTop: 6 },
   advancedToggle: {
     marginTop: 12,
     marginBottom: 12,