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/workbox-background-sync/lib/QueueDb.d.ts

@@ -0,0 +1,90 @@
+import { RequestData } from './StorableRequest.js';
+import '../_version.js';
+export interface UnidentifiedQueueStoreEntry {
+    requestData: RequestData;
+    timestamp: number;
+    id?: number;
+    queueName?: string;
+    metadata?: object;
+}
+export interface QueueStoreEntry extends UnidentifiedQueueStoreEntry {
+    id: number;
+}
+/**
+ * A class to interact directly an IndexedDB created specifically to save and
+ * retrieve QueueStoreEntries. This class encapsulates all the schema details
+ * to store the representation of a Queue.
+ *
+ * @private
+ */
+export declare class QueueDb {
+    private _db;
+    /**
+     * Add QueueStoreEntry to underlying db.
+     *
+     * @param {UnidentifiedQueueStoreEntry} entry
+     */
+    addEntry(entry: UnidentifiedQueueStoreEntry): Promise<void>;
+    /**
+     * Returns the first entry id in the ObjectStore.
+     *
+     * @return {number | undefined}
+     */
+    getFirstEntryId(): Promise<number | undefined>;
+    /**
+     * Get all the entries filtered by index
+     *
+     * @param queueName
+     * @return {Promise<QueueStoreEntry[]>}
+     */
+    getAllEntriesByQueueName(queueName: string): Promise<QueueStoreEntry[]>;
+    /**
+     * Returns the number of entries filtered by index
+     *
+     * @param queueName
+     * @return {Promise<number>}
+     */
+    getEntryCountByQueueName(queueName: string): Promise<number>;
+    /**
+     * Deletes a single entry by id.
+     *
+     * @param {number} id the id of the entry to be deleted
+     */
+    deleteEntry(id: number): Promise<void>;
+    /**
+     *
+     * @param queueName
+     * @returns {Promise<QueueStoreEntry | undefined>}
+     */
+    getFirstEntryByQueueName(queueName: string): Promise<QueueStoreEntry | undefined>;
+    /**
+     *
+     * @param queueName
+     * @returns {Promise<QueueStoreEntry | undefined>}
+     */
+    getLastEntryByQueueName(queueName: string): Promise<QueueStoreEntry | undefined>;
+    /**
+     * Returns either the first or the last entries, depending on direction.
+     * Filtered by index.
+     *
+     * @param {IDBCursorDirection} direction
+     * @param {IDBKeyRange} query
+     * @return {Promise<QueueStoreEntry | undefined>}
+     * @private
+     */
+    getEndEntryFromIndex(query: IDBKeyRange, direction: IDBCursorDirection): Promise<QueueStoreEntry | undefined>;
+    /**
+     * Returns an open connection to the database.
+     *
+     * @private
+     */
+    private getDb;
+    /**
+     * Upgrades QueueDB
+     *
+     * @param {IDBPDatabase<QueueDBSchema>} db
+     * @param {number} oldVersion
+     * @private
+     */
+    private _upgradeDb;
+}