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/QueueStore.js

@@ -0,0 +1,152 @@
+/*
+  Copyright 2018 Google LLC
+
+  Use of this source code is governed by an MIT-style
+  license that can be found in the LICENSE file or at
+  https://opensource.org/licenses/MIT.
+*/
+import { assert } from 'workbox-core/_private/assert.js';
+import { QueueDb, } from './QueueDb.js';
+import '../_version.js';
+/**
+ * A class to manage storing requests from a Queue in IndexedDB,
+ * indexed by their queue name for easier access.
+ *
+ * Most developers will not need to access this class directly;
+ * it is exposed for advanced use cases.
+ */
+export class QueueStore {
+    /**
+     * Associates this instance with a Queue instance, so entries added can be
+     * identified by their queue name.
+     *
+     * @param {string} queueName
+     */
+    constructor(queueName) {
+        this._queueName = queueName;
+        this._queueDb = new QueueDb();
+    }
+    /**
+     * Append an entry last in the queue.
+     *
+     * @param {Object} entry
+     * @param {Object} entry.requestData
+     * @param {number} [entry.timestamp]
+     * @param {Object} [entry.metadata]
+     */
+    async pushEntry(entry) {
+        if (process.env.NODE_ENV !== 'production') {
+            assert.isType(entry, 'object', {
+                moduleName: 'workbox-background-sync',
+                className: 'QueueStore',
+                funcName: 'pushEntry',
+                paramName: 'entry',
+            });
+            assert.isType(entry.requestData, 'object', {
+                moduleName: 'workbox-background-sync',
+                className: 'QueueStore',
+                funcName: 'pushEntry',
+                paramName: 'entry.requestData',
+            });
+        }
+        // Don't specify an ID since one is automatically generated.
+        delete entry.id;
+        entry.queueName = this._queueName;
+        await this._queueDb.addEntry(entry);
+    }
+    /**
+     * Prepend an entry first in the queue.
+     *
+     * @param {Object} entry
+     * @param {Object} entry.requestData
+     * @param {number} [entry.timestamp]
+     * @param {Object} [entry.metadata]
+     */
+    async unshiftEntry(entry) {
+        if (process.env.NODE_ENV !== 'production') {
+            assert.isType(entry, 'object', {
+                moduleName: 'workbox-background-sync',
+                className: 'QueueStore',
+                funcName: 'unshiftEntry',
+                paramName: 'entry',
+            });
+            assert.isType(entry.requestData, 'object', {
+                moduleName: 'workbox-background-sync',
+                className: 'QueueStore',
+                funcName: 'unshiftEntry',
+                paramName: 'entry.requestData',
+            });
+        }
+        const firstId = await this._queueDb.getFirstEntryId();
+        if (firstId) {
+            // Pick an ID one less than the lowest ID in the object store.
+            entry.id = firstId - 1;
+        }
+        else {
+            // Otherwise let the auto-incrementor assign the ID.
+            delete entry.id;
+        }
+        entry.queueName = this._queueName;
+        await this._queueDb.addEntry(entry);
+    }
+    /**
+     * Removes and returns the last entry in the queue matching the `queueName`.
+     *
+     * @return {Promise<QueueStoreEntry|undefined>}
+     */
+    async popEntry() {
+        return this._removeEntry(await this._queueDb.getLastEntryByQueueName(this._queueName));
+    }
+    /**
+     * Removes and returns the first entry in the queue matching the `queueName`.
+     *
+     * @return {Promise<QueueStoreEntry|undefined>}
+     */
+    async shiftEntry() {
+        return this._removeEntry(await this._queueDb.getFirstEntryByQueueName(this._queueName));
+    }
+    /**
+     * Returns all entries in the store matching the `queueName`.
+     *
+     * @param {Object} options See {@link workbox-background-sync.Queue~getAll}
+     * @return {Promise<Array<Object>>}
+     */
+    async getAll() {
+        return await this._queueDb.getAllEntriesByQueueName(this._queueName);
+    }
+    /**
+     * Returns the number of entries in the store matching the `queueName`.
+     *
+     * @param {Object} options See {@link workbox-background-sync.Queue~size}
+     * @return {Promise<number>}
+     */
+    async size() {
+        return await this._queueDb.getEntryCountByQueueName(this._queueName);
+    }
+    /**
+     * Deletes the entry for the given ID.
+     *
+     * WARNING: this method does not ensure the deleted entry belongs to this
+     * queue (i.e. matches the `queueName`). But this limitation is acceptable
+     * as this class is not publicly exposed. An additional check would make
+     * this method slower than it needs to be.
+     *
+     * @param {number} id
+     */
+    async deleteEntry(id) {
+        await this._queueDb.deleteEntry(id);
+    }
+    /**
+     * Removes and returns the first or last entry in the queue (based on the
+     * `direction` argument) matching the `queueName`.
+     *
+     * @return {Promise<QueueStoreEntry|undefined>}
+     * @private
+     */
+    async _removeEntry(entry) {
+        if (entry) {
+            await this.deleteEntry(entry.id);
+        }
+        return entry;
+    }
+}