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/vocabularies/jtd/error.js

@@ -0,0 +1,20 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.typeErrorParams = exports.typeErrorMessage = exports.typeError = void 0;
+const codegen_1 = require("../../compile/codegen");
+function typeError(t) {
+    return {
+        message: (cxt) => typeErrorMessage(cxt, t),
+        params: (cxt) => typeErrorParams(cxt, t),
+    };
+}
+exports.typeError = typeError;
+function typeErrorMessage({ parentSchema }, t) {
+    return (parentSchema === null || parentSchema === void 0 ? void 0 : parentSchema.nullable) ? `must be ${t} or null` : `must be ${t}`;
+}
+exports.typeErrorMessage = typeErrorMessage;
+function typeErrorParams({ parentSchema }, t) {
+    return (0, codegen_1._) `{type: ${t}, nullable: ${!!(parentSchema === null || parentSchema === void 0 ? void 0 : parentSchema.nullable)}}`;
+}
+exports.typeErrorParams = typeErrorParams;
+//# sourceMappingURL=error.js.map