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/resolve/lib/node-modules-paths.js

@@ -0,0 +1,45 @@
+var path = require('path');
+var parse = path.parse || require('path-parse'); // eslint-disable-line global-require
+
+var driveLetterRegex = /^([A-Za-z]:)/;
+var uncPathRegex = /^\\\\/;
+
+var getNodeModulesDirs = function getNodeModulesDirs(absoluteStart, modules) {
+    var prefix = '/';
+    if (driveLetterRegex.test(absoluteStart)) {
+        prefix = '';
+    } else if (uncPathRegex.test(absoluteStart)) {
+        prefix = '\\\\';
+    }
+
+    var paths = [absoluteStart];
+    var parsed = parse(absoluteStart);
+    while (parsed.dir !== paths[paths.length - 1]) {
+        paths.push(parsed.dir);
+        parsed = parse(parsed.dir);
+    }
+
+    return paths.reduce(function (dirs, aPath) {
+        return dirs.concat(modules.map(function (moduleDir) {
+            return path.resolve(prefix, aPath, moduleDir);
+        }));
+    }, []);
+};
+
+module.exports = function nodeModulesPaths(start, opts, request) {
+    var modules = opts && opts.moduleDirectory
+        ? [].concat(opts.moduleDirectory)
+        : ['node_modules'];
+
+    if (opts && typeof opts.paths === 'function') {
+        return opts.paths(
+            request,
+            start,
+            function () { return getNodeModulesDirs(start, modules); },
+            opts
+        );
+    }
+
+    var dirs = getNodeModulesDirs(start, modules);
+    return opts && opts.paths ? dirs.concat(opts.paths) : dirs;
+};