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/items2020.js

@@ -0,0 +1,30 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+const codegen_1 = require("../../compile/codegen");
+const util_1 = require("../../compile/util");
+const code_1 = require("../code");
+const additionalItems_1 = require("./additionalItems");
+const error = {
+    message: ({ params: { len } }) => (0, codegen_1.str) `must NOT have more than ${len} items`,
+    params: ({ params: { len } }) => (0, codegen_1._) `{limit: ${len}}`,
+};
+const def = {
+    keyword: "items",
+    type: "array",
+    schemaType: ["object", "boolean"],
+    before: "uniqueItems",
+    error,
+    code(cxt) {
+        const { schema, parentSchema, it } = cxt;
+        const { prefixItems } = parentSchema;
+        it.items = true;
+        if ((0, util_1.alwaysValidSchema)(it, schema))
+            return;
+        if (prefixItems)
+            (0, additionalItems_1.validateAdditionalItems)(cxt, prefixItems);
+        else
+            cxt.ok((0, code_1.validateArray)(cxt));
+    },
+};
+exports.default = def;
+//# sourceMappingURL=items2020.js.map