Add progressive web app companion for cross-platform access

Vite + TypeScript PWA that mirrors the Android app's core features:
- Pre-processed shelter data (build-time UTM33N→WGS84 conversion)
- Leaflet map with shelter markers, user location, and offline tiles
- Canvas compass arrow (ported from DirectionArrowView.kt)
- IndexedDB shelter cache with 7-day staleness check
- Service worker with CacheFirst tiles and precached app shell
- i18n for en, nb, nn (ported from Android strings.xml)
- iOS/Android compass handling with low-pass filter
- Respects user map interaction (no auto-snap on pan/zoom)
- Build revision cache-breaker for reliable SW updates

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pwa/node_modules/call-bind-apply-helpers/applyBind.d.ts

@@ -0,0 +1,19 @@
+import actualApply from './actualApply';
+
+type TupleSplitHead<T extends any[], N extends number> = T['length'] extends N
+  ? T
+  : T extends [...infer R, any]
+  ? TupleSplitHead<R, N>
+  : never
+
+type TupleSplitTail<T, N extends number, O extends any[] = []> = O['length'] extends N
+  ? T
+  : T extends [infer F, ...infer R]
+  ? TupleSplitTail<[...R], N, [...O, F]>
+  : never
+
+type TupleSplit<T extends any[], N extends number> = [TupleSplitHead<T, N>, TupleSplitTail<T, N>]
+
+declare function applyBind(...args: TupleSplit<Parameters<typeof actualApply>, 2>[1]): ReturnType<typeof actualApply>;
+
+export = applyBind;