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/strip-comments/lib/compile.js

@@ -0,0 +1,63 @@
+'use strict';
+
+const compile = (cst, options = {}) => {
+  const keepProtected = options.safe === true || options.keepProtected === true;
+  let firstSeen = false;
+
+  const walk = (node, parent) => {
+    let output = '';
+    let inner;
+    let lines;
+
+    for (const child of node.nodes) {
+      switch (child.type) {
+        case 'block':
+          if (options.first && firstSeen === true) {
+            output += walk(child, node);
+            break;
+          }
+
+          if (options.preserveNewlines === true) {
+            inner = walk(child, node);
+            lines = inner.split('\n');
+            output += '\n'.repeat(lines.length - 1);
+            break;
+          }
+
+          if (keepProtected === true && child.protected === true) {
+            output += walk(child, node);
+            break;
+          }
+
+          firstSeen = true;
+          break;
+        case 'line':
+          if (options.first && firstSeen === true) {
+            output += child.value;
+            break;
+          }
+
+          if (keepProtected === true && child.protected === true) {
+            output += child.value;
+          }
+
+          firstSeen = true;
+          break;
+        case 'open':
+        case 'close':
+        case 'text':
+        case 'newline':
+        default: {
+          output += child.value || '';
+          break;
+        }
+      }
+    }
+
+    return output;
+  };
+
+  return walk(cst);
+};
+
+module.exports = compile;