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/refs/json-schema-2020-12/index.js

@@ -0,0 +1,30 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+const metaSchema = require("./schema.json");
+const applicator = require("./meta/applicator.json");
+const unevaluated = require("./meta/unevaluated.json");
+const content = require("./meta/content.json");
+const core = require("./meta/core.json");
+const format = require("./meta/format-annotation.json");
+const metadata = require("./meta/meta-data.json");
+const validation = require("./meta/validation.json");
+const META_SUPPORT_DATA = ["/properties"];
+function addMetaSchema2020($data) {
+    ;
+    [
+        metaSchema,
+        applicator,
+        unevaluated,
+        content,
+        core,
+        with$data(this, format),
+        metadata,
+        with$data(this, validation),
+    ].forEach((sch) => this.addMetaSchema(sch, undefined, false));
+    return this;
+    function with$data(ajv, sch) {
+        return $data ? ajv.$dataMetaSchema(sch, META_SUPPORT_DATA) : sch;
+    }
+}
+exports.default = addMetaSchema2020;
+//# sourceMappingURL=index.js.map