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/applicator/thenElse.js

@@ -0,0 +1,13 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+const util_1 = require("../../compile/util");
+const def = {
+    keyword: ["then", "else"],
+    schemaType: ["object", "boolean"],
+    code({ keyword, parentSchema, it }) {
+        if (parentSchema.if === undefined)
+            (0, util_1.checkStrictMode)(it, `"${keyword}" without "if" is ignored`);
+    },
+};
+exports.default = def;
+//# sourceMappingURL=thenElse.js.map