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/ajv/dist/compile/resolve.d.ts

@@ -0,0 +1,12 @@
+import type { AnySchema, AnySchemaObject, UriResolver } from "../types";
+import type Ajv from "../ajv";
+import type { URIComponent } from "fast-uri";
+export type LocalRefs = {
+    [Ref in string]?: AnySchemaObject;
+};
+export declare function inlineRef(schema: AnySchema, limit?: boolean | number): boolean;
+export declare function getFullPath(resolver: UriResolver, id?: string, normalize?: boolean): string;
+export declare function _getFullPath(resolver: UriResolver, p: URIComponent): string;
+export declare function normalizeId(id: string | undefined): string;
+export declare function resolveUrl(resolver: UriResolver, baseId: string, id: string): string;
+export declare function getSchemaRefs(this: Ajv, schema: AnySchema, baseId: string): LocalRefs;