M2b: Android skeleton, :core:model contract, :domain passing all vectors

Gradle project in android/ with every module of SPEC §6.2 (build-logic convention plugins, version catalog,
architecture check in check), :core:model types and repository interfaces of §14.2.4 and §14.5, :domain
implementing §14.5.2 and §14.5.4 (125 vector cases), scenario-driven fakes with the empty scenario, Room 3
entities and KvittDatabase v1 with exported schema, :app shell with Hilt, en/sv strings with MissingTranslation
as a lint error, Roborazzi goldens of the empty screen in light and dark.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

android/build.gradle.kts

@@ -0,0 +1,12 @@
+// Plugins are declared once here (apply false) so every module resolves them from the same classloader.
+plugins {
+    alias(libs.plugins.android.application) apply false
+    alias(libs.plugins.android.library) apply false
+    alias(libs.plugins.kotlin.jvm) apply false
+    alias(libs.plugins.kotlin.compose) apply false
+    alias(libs.plugins.kotlin.serialization) apply false
+    alias(libs.plugins.ksp) apply false
+    alias(libs.plugins.hilt) apply false
+    alias(libs.plugins.room3) apply false
+    alias(libs.plugins.roborazzi) apply false
+}