Add per-app configurable settings screen

Replaces "hide everything for every scoped app" with per-package, per-feature
toggles, backed by SharedPreferences the hook reads via XSharedPreferences.
A package with no explicit entry still gets every feature hidden, keeping
prior behavior as the default.

Adds a launcher activity so the settings screen is directly reachable.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

app/src/main/AndroidManifest.xml

@@ -15,5 +15,15 @@
             android:name="xposeddescription"
             android:value="@string/module_description" />
 
+        <activity
+            android:name=".SettingsActivity"
+            android:exported="true"
+            android:label="@string/app_name">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+
     </application>
 </manifest>