feat: use Capacitor Geolocation to prompt and get native location on Android

frontend/src/utils/geolocation.ts

@@ -0,0 +1,54 @@
+import { Geolocation } from '@capacitor/geolocation';
+
+export interface DeviceLocation {
+  latitude: number;
+  longitude: number;
+}
+
+export async function getDeviceLocation(): Promise<DeviceLocation | null> {
+  try {
+    // Request permission at native level (essential for Android app packaging)
+    const permissionStatus = await Geolocation.requestPermissions();
+    if (permissionStatus.location === 'granted' || permissionStatus.coarseLocation === 'granted') {
+      const position = await Geolocation.getCurrentPosition({
+        enableHighAccuracy: true,
+        timeout: 5000
+      });
+      if (position && position.coords) {
+        console.log('[Geolocation] Acquired coordinates via Capacitor Geolocation:', position.coords.latitude, position.coords.longitude);
+        return {
+          latitude: position.coords.latitude,
+          longitude: position.coords.longitude
+        };
+      }
+    }
+  } catch (error) {
+    console.warn('[Geolocation] Capacitor plugin failed/unavailable, falling back to browser Geolocation:', error);
+  }
+
+  // Fallback to standard web browser Geolocation API
+  try {
+    const position = await new Promise<GeolocationPosition | null>((resolve) => {
+      if (!navigator.geolocation) {
+        resolve(null);
+      } else {
+        navigator.geolocation.getCurrentPosition(
+          (p) => resolve(p),
+          () => resolve(null),
+          { timeout: 4000, enableHighAccuracy: true }
+        );
+      }
+    });
+    if (position && position.coords) {
+      console.log('[Geolocation] Acquired coordinates via Web Geolocation:', position.coords.latitude, position.coords.longitude);
+      return {
+        latitude: position.coords.latitude,
+        longitude: position.coords.longitude
+      };
+    }
+  } catch (e) {
+    console.error('[Geolocation] Browser Geolocation failed:', e);
+  }
+
+  return null;
+}