feat: Run APK download as foreground (dataSync) work

Long transfers — especially over Tor — can exceed WorkManager's
~10-minute background execution window, getting the worker stopped and
rescheduled repeatedly. Promote the download to foreground work with a
progress notification (cancel action included) so it can run to
completion.

- setForeground() with FOREGROUND_SERVICE_TYPE_DATA_SYNC; the manifest
  already holds the FOREGROUND_SERVICE_DATA_SYNC permission, and the
  WorkManager SystemForegroundService is merged with type dataSync.
- If Android 12+ rejects the promotion (app backgrounded), the worker
  logs and continues as regular background work, relying on Range-resume.
- Notification updates are throttled to 5% steps and degrade gracefully
  without POST_NOTIFICATIONS.

Addresses the Codex review finding on ApkDownloadWorker.

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

app/src/main/AndroidManifest.xml

@@ -151,5 +151,12 @@
             android:label="Share BitChat"
             android:theme="@style/Theme.BitchatAndroid"
             android:launchMode="singleTop" />
+
+        <!-- Declare the foreground service type for WorkManager's foreground
+             service so the APK download worker can run as dataSync work -->
+        <service
+            android:name="androidx.work.impl.foreground.SystemForegroundService"
+            android:foregroundServiceType="dataSync"
+            tools:node="merge" />
     </application>
 </manifest>

app/src/main/java/com/bitchat/android/util/ApkDownloadWorker.kt

@@ -1,15 +1,26 @@
 package com.bitchat.android.util
 
+import android.app.NotificationChannel
+import android.app.NotificationManager
 import android.content.Context
+import android.content.pm.ServiceInfo
+import android.os.Build
 import android.util.Log
+import androidx.core.app.NotificationCompat
 import androidx.work.CoroutineWorker
 import androidx.work.Data
+import androidx.work.ForegroundInfo
+import androidx.work.WorkManager
 import androidx.work.WorkerParameters
+import com.bitchat.android.R
 
 /**
  * WorkManager worker that downloads the universal APK in the background.
  * Survives app backgrounding and process death. Transient network errors are
  * retried with backoff; partial downloads resume via HTTP Range requests.
+ *
+ * Runs as foreground (dataSync) work when possible so slow transfers (e.g.
+ * over Tor) are not killed by WorkManager's background execution window.
  */
 class ApkDownloadWorker(
     appContext: Context,
@@ -28,15 +39,34 @@ class ApkDownloadWorker(
         const val KEY_RESUMABLE_PERCENT = "resumable_percent"
 
         private const val MAX_RETRIES = 3
+
+        private const val CHANNEL_ID = "apk_download"
+        private const val NOTIFICATION_ID = 4201
+        private const val NOTIFY_STEP_PERCENT = 5
     }
 
     private val apkManager = UniversalApkManager(applicationContext)
+    private val notificationManager =
+        applicationContext.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
+
+    private var lastNotifiedProgress = -NOTIFY_STEP_PERCENT
 
     override suspend fun doWork(): Result {
         Log.d(TAG, "Starting APK download work")
 
+        // Promote to foreground so long transfers aren't stopped by the
+        // ~10-minute background execution window. Android 12+ can reject the
+        // promotion when the app is backgrounded — continue as regular
+        // background work and rely on Range-resume in that case.
+        try {
+            setForeground(createForegroundInfo(apkManager.getPartialDownloadProgress() ?: 0))
+        } catch (e: Exception) {
+            Log.w(TAG, "Could not promote download to foreground work", e)
+        }
+
         val result = apkManager.downloadUniversalApk { progress ->
             setProgressAsync(Data.Builder().putInt(KEY_PROGRESS, progress).build())
+            updateNotification(progress)
         }
 
         return if (result.isSuccess) {
@@ -69,4 +99,63 @@ class ApkDownloadWorker(
             Result.failure(outputData)
         }
     }
+
+    override suspend fun getForegroundInfo(): ForegroundInfo {
+        return createForegroundInfo(apkManager.getPartialDownloadProgress() ?: 0)
+    }
+
+    private fun createForegroundInfo(progress: Int): ForegroundInfo {
+        ensureChannel()
+        val notification = buildNotification(progress)
+        return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+            ForegroundInfo(
+                NOTIFICATION_ID,
+                notification,
+                ServiceInfo.FOREGROUND_SERVICE_TYPE_DATA_SYNC
+            )
+        } else {
+            ForegroundInfo(NOTIFICATION_ID, notification)
+        }
+    }
+
+    private fun buildNotification(progress: Int): android.app.Notification {
+        val cancelIntent = WorkManager.getInstance(applicationContext)
+            .createCancelPendingIntent(id)
+
+        return NotificationCompat.Builder(applicationContext, CHANNEL_ID)
+            .setContentTitle(applicationContext.getString(R.string.apk_download_notification_title))
+            .setSmallIcon(R.drawable.ic_notification)
+            .setOngoing(true)
+            .setOnlyAlertOnce(true)
+            .setProgress(100, progress, progress <= 0)
+            .addAction(
+                android.R.drawable.ic_delete,
+                applicationContext.getString(android.R.string.cancel),
+                cancelIntent
+            )
+            .build()
+    }
+
+    private fun updateNotification(progress: Int) {
+        if (progress - lastNotifiedProgress < NOTIFY_STEP_PERCENT) return
+        lastNotifiedProgress = progress
+        try {
+            notificationManager.notify(NOTIFICATION_ID, buildNotification(progress))
+        } catch (e: Exception) {
+            // Missing POST_NOTIFICATIONS permission just drops the update;
+            // the download itself is unaffected.
+            Log.w(TAG, "Could not update download notification", e)
+        }
+    }
+
+    private fun ensureChannel() {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            val channel = NotificationChannel(
+                CHANNEL_ID,
+                applicationContext.getString(R.string.apk_download_channel_name),
+                NotificationManager.IMPORTANCE_LOW
+            )
+            notificationManager.createNotificationChannel(channel)
+        }
+    }
 }

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

@@ -185,6 +185,8 @@
   <string name="prepare_apk_required">Please prepare the app for sharing first.</string>
   <string name="prepare_apk_download_interrupted">Download interrupted</string>
   <string name="prepare_apk_download_cancelled">Download cancelled</string>
+  <string name="apk_download_notification_title">Downloading universal APK</string>
+  <string name="apk_download_channel_name">APK downloads</string>
 
   <!-- Hotspot Sharing -->
   <string name="hotspot_share_via">Share via Hotspot</string>