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/rules.d.ts

@@ -0,0 +1,28 @@
+import type { AddedKeywordDefinition } from "../types";
+declare const _jsonTypes: readonly ["string", "number", "integer", "boolean", "null", "object", "array"];
+export type JSONType = (typeof _jsonTypes)[number];
+export declare function isJSONType(x: unknown): x is JSONType;
+type ValidationTypes = {
+    [K in JSONType]: boolean | RuleGroup | undefined;
+};
+export interface ValidationRules {
+    rules: RuleGroup[];
+    post: RuleGroup;
+    all: {
+        [Key in string]?: boolean | Rule;
+    };
+    keywords: {
+        [Key in string]?: boolean;
+    };
+    types: ValidationTypes;
+}
+export interface RuleGroup {
+    type?: JSONType;
+    rules: Rule[];
+}
+export interface Rule {
+    keyword: string;
+    definition: AddedKeywordDefinition;
+}
+export declare function getRules(): ValidationRules;
+export {};