fix(fdroid): drop Google Play Core so the scanner accepts the APK; prep v0.1.15

F-Droid's APK scanner rejected v0.1.14: 6 com.google.android.play.core.*
(SplitInstall/SplitCompat/tasks) references. They came from Flutter's
io.flutter.embedding.engine.deferredcomponents.PlayStoreDeferredComponentManager
being pinned by our over-broad '-keep class io.flutter.** { *; }' ProGuard
rule — Tane uses no deferred components, so R8 should shrink that manager
away (as it does for immich and other Flutter F-Droid apps, which don't
carry such a keep). Narrow the keep to io.flutter.plugins.**; JNI-critical
embedding classes (FlutterJNI, …) stay via the embedding AAR's own consumer
ProGuard rules — verified the built APK still contains FlutterJNI and no
com.google.android.play.core.* at all. Also exclude the com.google.android.play
group at the dependency level (belt-and-suspenders) + -dontwarn.

Bumps to 0.1.15 (+17); fdroid recipe versionCodes 171/172/173.

apps/app_seeds/android/app/build.gradle.kts

@@ -97,6 +97,17 @@ dependencies {
     coreLibraryDesugaring("com.android.tools:desugar_jdk_libs:2.1.4")
 }
 
+// F-Droid: Flutter's embedding transitively pulls Google Play Core (deferred
+// components / split install — com.google.android.play.core.*), which F-Droid's
+// scanner rejects as a proprietary Google dependency. Tane does not use deferred
+// components, so drop the whole com.google.android.play group; those split-install
+// code paths are never reached. R8 keeps the referenced classes otherwise, so the
+// exclusion (not shrinking) is what removes them; -dontwarn in proguard-rules.pro
+// silences the now-dangling compile-time references.
+configurations.all {
+    exclude(group = "com.google.android.play")
+}
+
 // F-Droid builds one split APK per ABI (smaller downloads than a universal
 // APK) and needs each split to carry a distinct versionCode so its repo can
 // tell them apart; `flutter build apk --split-per-abi` alone gives every