fix: prevent beta flags from restoring on fresh install

Exclude the beta-flags DataStore from Android Auto Backup and reset
non-persistent beta flags when a fresh install or backup restore is
detected using a noBackupFilesDir marker file.

Signed-off-by: Brandon McAnsh <git@bmcreations.dev>

Author: bmc08gt

apps/flipcash/app/src/main/AndroidManifest.xml

@@ -43,6 +43,8 @@
     <application
         android:name="com.flipcash.app.FlipcashApp"
         android:allowBackup="true"
+        android:fullBackupContent="@xml/backup_rules"
+        android:dataExtractionRules="@xml/data_extraction_rules"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
         android:largeHeap="true"

apps/flipcash/app/src/main/res/xml/backup_rules.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<full-backup-content>
+    <exclude
+        domain="file"
+        path="datastore/beta-flags.preferences_pb" />
+</full-backup-content>

apps/flipcash/app/src/main/res/xml/data_extraction_rules.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<data-extraction-rules>
+    <cloud-backup>
+        <exclude
+            domain="file"
+            path="datastore/beta-flags.preferences_pb" />
+    </cloud-backup>
+    <device-transfer>
+        <exclude
+            domain="file"
+            path="datastore/beta-flags.preferences_pb" />
+    </device-transfer>
+</data-extraction-rules>

apps/flipcash/shared/featureflags/src/main/kotlin/com/flipcash/app/featureflags/internal/InternalFeatureFlagController.kt

@@ -21,6 +21,7 @@ import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
+import java.io.File
 import javax.inject.Inject
 
 internal class InternalFeatureFlagController @Inject constructor(
@@ -49,6 +50,15 @@ internal class InternalFeatureFlagController @Inject constructor(
         FeatureFlag.entries
             .filter { it.launched }
             .onEach { reset(it) }
+
+        // Clear beta flags restored from backup on fresh install.
+        // noBackupFilesDir is never included in Auto Backup, so the marker
+        // file won't exist after a restore — triggering a full reset.
+        val marker = File(context.noBackupFilesDir, "beta-flags-initialized")
+        if (!marker.exists()) {
+            reset()
+            marker.createNewFile()
+        }
     }
 
     override fun enableBetaFeatures() {