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/object-inspect/package-support.json

@@ -0,0 +1,20 @@
+{
+  "versions": [
+    {
+      "version": "*",
+      "target": {
+        "node": "all"
+      },
+      "response": {
+        "type": "time-permitting"
+      },
+      "backing": {
+        "npm-funding": true,
+        "donations": [
+          "https://github.com/ljharb",
+          "https://tidelift.com/funding/github/npm/object-inspect"
+        ]
+      }
+    }
+  ]
+}