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/loupe/lib/string.js

@@ -0,0 +1,24 @@
+import { truncate } from './helpers.js';
+const stringEscapeChars = new RegExp("['\\u0000-\\u001f\\u007f-\\u009f\\u00ad\\u0600-\\u0604\\u070f\\u17b4\\u17b5" +
+    '\\u200c-\\u200f\\u2028-\\u202f\\u2060-\\u206f\\ufeff\\ufff0-\\uffff]', 'g');
+const escapeCharacters = {
+    '\b': '\\b',
+    '\t': '\\t',
+    '\n': '\\n',
+    '\f': '\\f',
+    '\r': '\\r',
+    "'": "\\'",
+    '\\': '\\\\',
+};
+const hex = 16;
+const unicodeLength = 4;
+function escape(char) {
+    return (escapeCharacters[char] ||
+        `\\u${`0000${char.charCodeAt(0).toString(hex)}`.slice(-unicodeLength)}`);
+}
+export default function inspectString(string, options) {
+    if (stringEscapeChars.test(string)) {
+        string = string.replace(stringEscapeChars, escape);
+    }
+    return options.stylize(`'${truncate(string, options.truncate - 2)}'`, 'string');
+}