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/rollup/dist/loadConfigFile.d.ts

@@ -0,0 +1,20 @@
+import type { LogHandler, MergedRollupOptions, RollupLog } from './rollup';
+
+export interface BatchWarnings {
+	add: (warning: RollupLog) => void;
+	readonly count: number;
+	flush: () => void;
+	log: LogHandler;
+	readonly warningOccurred: boolean;
+}
+
+export type LoadConfigFile = typeof loadConfigFile;
+
+export function loadConfigFile(
+	fileName: string,
+	commandOptions: any,
+	watchMode?: boolean
+): Promise<{
+	options: MergedRollupOptions[];
+	warnings: BatchWarnings;
+}>;