feat(android): :app module skeleton — Compose Activity + manifest

M8 phase 1.2. AndroidManifest declares FGS mediaPlayback +
POST_NOTIFICATIONS permissions ahead of the player phase. Activity
hosts a single Compose Scaffold for now; nav graph lands in phase 5.

Launcher icons reused from flutter_client/ (same applicationId means
same brand at cutover). MinstrelApplication referenced in manifest
but the class itself lands in Task 1.3 — manifest class names are
resolved at install time, not build time, so the intermediate commit
still builds.

@AndroidEntryPoint deferred to Task 1.3 alongside @HiltAndroidApp on
MinstrelApplication (Hilt KSP errors without an annotated Application).

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

android/app/src/main/res/values/strings.xml

@@ -0,0 +1,3 @@
+<resources>
+    <string name="app_name">Minstrel</string>
+</resources>

android/app/src/main/res/values/themes.xml

@@ -0,0 +1,8 @@
+<resources>
+    <!-- Compose-MaterialTheme owns visual theming at runtime. This <style> only
+         suppresses the action bar and sets a base window background to prevent
+         the white flash during cold start. -->
+    <style name="Theme.Minstrel" parent="android:Theme.Material.NoActionBar">
+        <item name="android:windowBackground">@android:color/black</item>
+    </style>
+</resources>

android/app/src/main/res/xml/backup_rules.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Backups disabled. Room schema rebuild on cutover is cheap; sync controller
+     refills from server. -->
+<full-backup-content>
+    <exclude domain="database" />
+    <exclude domain="sharedpref" />
+</full-backup-content>

android/app/src/main/res/xml/data_extraction_rules.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<data-extraction-rules>
+    <cloud-backup>
+        <exclude domain="database" />
+        <exclude domain="sharedpref" />
+    </cloud-backup>
+    <device-transfer>
+        <exclude domain="database" />
+        <exclude domain="sharedpref" />
+    </device-transfer>
+</data-extraction-rules>