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>

app/build.gradle.kts

@@ -1,9 +1,16 @@
+import java.util.Properties
+
 plugins {
     id("com.android.application")
     id("org.jetbrains.kotlin.android")
     id("com.google.devtools.ksp")
 }
 
+// Read version from shared version.properties
+val versionProps = Properties().apply {
+    rootProject.file("version.properties").inputStream().use { load(it) }
+}
+
 android {
     namespace = "no.naiv.tilfluktsrom"
     compileSdk = 35
@@ -12,8 +19,13 @@ android {
         applicationId = "no.naiv.tilfluktsrom"
         minSdk = 26
         targetSdk = 35
-        versionCode = 1
-        versionName = "1.0.0"
+        versionCode = versionProps.getProperty("versionCode").toInt()
+        versionName = "${versionProps.getProperty("versionMajor")}." +
+            "${versionProps.getProperty("versionMinor")}." +
+            versionProps.getProperty("versionPatch")
+
+        // Make version available in BuildConfig
+        buildConfigField("String", "VERSION_DISPLAY", "\"$versionName\"")
     }
 
     buildTypes {
@@ -29,6 +41,7 @@ android {
 
     buildFeatures {
         viewBinding = true
+        buildConfig = true
     }
 
     compileOptions {