feat(android): bootstrap native Android module — Gradle + version catalog

M8 phase 1.1: empty multi-project Gradle scaffold (root + :app
placeholder). Version catalog establishes pinned Kotlin/AGP/Compose/
Hilt/Room/Media3/etc. versions for the whole module.

Gradle wrapper (8.10) reused from flutter_client/ — the wrapper jar
is a bootstrap and respects distributionUrl from gradle-wrapper.properties.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

android/settings.gradle.kts

@@ -0,0 +1,22 @@
+pluginManagement {
+    repositories {
+        google {
+            content {
+                includeGroupByRegex("com\\.android.*")
+                includeGroupByRegex("com\\.google.*")
+                includeGroupByRegex("androidx.*")
+            }
+        }
+        mavenCentral()
+        gradlePluginPortal()
+    }
+}
+dependencyResolutionManagement {
+    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
+    repositories {
+        google()
+        mavenCentral()
+    }
+}
+rootProject.name = "Minstrel"
+include(":app")