Bundle shelter data in APK and add shared versioning

- Add scripts/fetch-shelters.sh: downloads Geonorge data, converts
  UTM33N→WGS84 via PWA script, copies to both Android assets and
  PWA public dirs
- Bundle pre-processed shelters.json (556 shelters) in APK assets
  so the app works immediately on first launch with no network
- ShelterRepository.seedFromAsset(): seeds Room DB from bundled
  JSON on first launch, marks as stale so network refresh is
  attempted in the background
- MainActivity.loadData(): seeds from asset before trying network,
  always attempts background refresh when data is stale
- Add version.properties (1.1.0, versionCode=2) as single source
  of truth for versioning
- build.gradle.kts reads version from properties file and exposes
  via BuildConfig
- Bump PWA version to 1.1.0 to match

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pwa/package.json

@@ -1,6 +1,6 @@
 {
   "name": "tilfluktsrom-pwa",
-  "version": "1.0.0",
+  "version": "1.1.0",
   "description": "Norwegian Emergency Shelter Finder - PWA",
   "type": "module",
   "scripts": {