M12f: :app invite links dropped while paired, push-token retry, private notifications, en/sv only (D-112, D-116)

- AppViewModel.onLink drops an invite link while paired (AC-2.6, D-084), so it never prefills S-1 later.
- PushTokens: a failed E-17 PUT (network, 429, 5xx) is kept by PushTokenRetry and sent again after each successful
  sync until accepted; a newer FID replaces it (AC-13.7).
- Notifications are VISIBILITY_PRIVATE with a generic public version (notif_generic_title, notif_generic_body):
  no description, amount, account or name on a secure lock screen (security review L-7).
- androidResources.localeFilters en, sv (SPEC G-8, AC-19.1).
- Tests: AppViewModelTest (links while paired and unpaired, AC-2.9 permission after the first finished successful
  sync), PushTokenRetryTest, NotificationPrivacyTest.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TQd3pEP9UeN2uifbHknQ7B

android/app/build.gradle.kts

@@ -28,6 +28,11 @@ android {
         versionCode = providers.gradleProperty("kvitt.versionCode").orElse("1").get().toInt()
         versionName = providers.gradleProperty("kvitt.versionName").orElse("dev").get()
     }
+    // SPEC G-8 and AC-19.1: the app is English (fallback) and Swedish only; library translations of other languages
+    // are left out of the APK.
+    androidResources {
+        localeFilters += listOf("en", "sv")
+    }
     // BuildConfig carries versionCode, versionName and DEBUG into AppBuildInfo (:data, D-041).
     buildFeatures {
         buildConfig = true