feat(appstore): add AppStore client features

- AppStoreJsBridge: JS bridge for native APK install, version check, update
- InstalledAppDao, InstalledApp entity: Room DB for tracking installed apps
- UpdateCheckerWorker: background update polling via WorkManager
- InstallerService: APK download + SHA-256 verify + PackageInstaller session
- Updated AndroidManifest: REQUEST_INSTALL_PACKAGES, FileProvider, receivers
- Updated MainActivity: notification channel, WorkManager, JS bridge wiring
- config.json: targetUrl = https://store.silverlabs.uk
- file_paths.xml: FileProvider paths for APK installs

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/src/main/AndroidManifest.xml

@@ -13,9 +13,15 @@
         android:maxSdkVersion="32"
         tools:ignore="ScopedStorage" />
 
-    <!-- Notifications for PWA push notifications -->
+    <!-- Notifications for PWA push notifications and app update alerts -->
     <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
 
+    <!-- APK installation for AppStore update flow -->
+    <uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES" />
+
+    <!-- DownloadManager for APK downloads -->
+    <uses-permission android:name="android.permission.DOWNLOAD_WITHOUT_NOTIFICATION" />
+
     <application
         android:allowBackup="true"
         android:dataExtractionRules="@xml/data_extraction_rules"
@@ -49,6 +55,33 @@
             android:theme="@style/Theme.SilverDROID.Fullscreen"
             android:windowSoftInputMode="adjustResize" />
 
+        <!-- FileProvider for sharing APK files to PackageInstaller on older APIs -->
+        <provider
+            android:name="androidx.core.content.FileProvider"
+            android:authorities="uk.silverlabs.silverdroid.fileprovider"
+            android:exported="false"
+            android:grantUriPermissions="true">
+            <meta-data
+                android:name="android.support.FILE_PROVIDER_PATHS"
+                android:resource="@xml/file_paths" />
+        </provider>
+
+        <!-- BroadcastReceiver for PackageInstaller session callbacks -->
+        <receiver
+            android:name=".update.InstallStatusReceiver"
+            android:exported="false">
+            <!-- PackageInstaller session status (no data URI) -->
+            <intent-filter>
+                <action android:name="uk.silverlabs.silverdroid.INSTALL_STATUS" />
+            </intent-filter>
+            <!-- System package events (require package: data URI) -->
+            <intent-filter>
+                <action android:name="android.intent.action.PACKAGE_REPLACED" />
+                <action android:name="android.intent.action.PACKAGE_ADDED" />
+                <data android:scheme="package" />
+            </intent-filter>
+        </receiver>
+
     </application>
 
 </manifest>

app/src/main/assets/config.json

@@ -1,7 +1,7 @@
 {
-  "appName": "SilverDesk Staging",
+  "appName": "SilverSHELL AppStore",
   "appVersion": "1.0.0",
-  "targetUrl": "https://silverdesk-staging.silverlabs.uk/",
+  "targetUrl": "https://store.silverlabs.uk",
   "showUrlBar": false,
   "allowNavigation": true
 }

app/src/main/kotlin/uk/silverlabs/silverdroid/MainActivity.kt

@@ -10,12 +10,18 @@ import androidx.compose.material3.Surface
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.ui.Modifier
 import androidx.lifecycle.lifecycleScope
+import androidx.work.ExistingPeriodicWorkPolicy
+import androidx.work.PeriodicWorkRequestBuilder
+import androidx.work.WorkManager
 import kotlinx.coroutines.launch
 import uk.silverlabs.silverdroid.config.RemoteConfigLoader
 import uk.silverlabs.silverdroid.tor.TorManager
 import uk.silverlabs.silverdroid.ui.theme.SilverDROIDTheme
+import uk.silverlabs.silverdroid.ui.webview.AppStoreJsBridge
 import uk.silverlabs.silverdroid.ui.webview.WasmWebView
+import uk.silverlabs.silverdroid.update.UpdateCheckerWorker
 import uk.silverlabs.silverdroid.vpn.WireGuardManager
+import java.util.concurrent.TimeUnit
 
 /**
  * SilverDROID - Configurable Android Browser
@@ -35,6 +41,18 @@ class MainActivity : ComponentActivity() {
         super.onCreate(savedInstanceState)
         enableEdgeToEdge()
 
+        // Create notification channel for app updates
+        UpdateCheckerWorker.createNotificationChannel(this)
+
+        // Register periodic update checker (every 6 hours, requires network)
+        val updateWorkRequest = PeriodicWorkRequestBuilder<UpdateCheckerWorker>(6, TimeUnit.HOURS)
+            .build()
+        WorkManager.getInstance(this).enqueueUniquePeriodicWork(
+            UpdateCheckerWorker.WORK_NAME,
+            ExistingPeriodicWorkPolicy.KEEP,
+            updateWorkRequest
+        )
+
         // Load configuration asynchronously with remote support
         lifecycleScope.launch {
             val config = RemoteConfigLoader.loadConfigWithRemote(this@MainActivity)
@@ -46,6 +64,12 @@ class MainActivity : ComponentActivity() {
             // Initialize Tor if configured
             config.tor?.let { torManager.initialize(it) }
 
+            // Create AppStore JS bridge for WebView ↔ native communication
+            val jsBridge = AppStoreJsBridge(
+                context = this@MainActivity,
+                scope = lifecycleScope
+            )
+
             setContent {
                 SilverDROIDTheme {
                     Surface(
@@ -70,9 +94,8 @@ class MainActivity : ComponentActivity() {
                         WasmWebView(
                             url = config.targetUrl,
                             appName = config.appName,
-                            onBackPressed = {
-                                finish()
-                            }
+                            onBackPressed = { finish() },
+                            jsInterface = jsBridge
                         )
                     }
                 }

app/src/main/kotlin/uk/silverlabs/silverdroid/data/InstalledAppDao.kt

@@ -0,0 +1,45 @@
+package uk.silverlabs.silverdroid.data
+
+import androidx.room.*
+import kotlinx.coroutines.flow.Flow
+import uk.silverlabs.silverdroid.data.model.InstalledApp
+
+@Dao
+interface InstalledAppDao {
+
+    @Query("SELECT * FROM installed_apps ORDER BY appName ASC")
+    fun getAllApps(): Flow<List<InstalledApp>>
+
+    @Query("SELECT * FROM installed_apps ORDER BY appName ASC")
+    suspend fun getAllAppsOnce(): List<InstalledApp>
+
+    @Query("SELECT * FROM installed_apps WHERE id = :id")
+    suspend fun getById(id: Long): InstalledApp?
+
+    @Query("SELECT * FROM installed_apps WHERE slug = :slug LIMIT 1")
+    suspend fun getBySlug(slug: String): InstalledApp?
+
+    @Query("SELECT * FROM installed_apps WHERE packageName = :packageName LIMIT 1")
+    suspend fun getByPackageName(packageName: String): InstalledApp?
+
+    @Query("SELECT * FROM installed_apps WHERE hasUpdate = 1")
+    fun getAppsWithPendingUpdates(): Flow<List<InstalledApp>>
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun insert(app: InstalledApp): Long
+
+    @Update
+    suspend fun update(app: InstalledApp)
+
+    @Delete
+    suspend fun delete(app: InstalledApp)
+
+    @Query("DELETE FROM installed_apps WHERE slug = :slug")
+    suspend fun deleteBySlug(slug: String)
+
+    @Query("UPDATE installed_apps SET hasUpdate = 0, installedVersion = :newVersion, pendingVersion = NULL, pendingDownloadUrl = NULL, pendingsha256 = NULL, pendingReleaseNotes = NULL WHERE slug = :slug")
+    suspend fun markUpdateInstalled(slug: String, newVersion: String)
+
+    @Query("SELECT COUNT(*) FROM installed_apps")
+    suspend fun getCount(): Int
+}

app/src/main/kotlin/uk/silverlabs/silverdroid/data/PwaDatabase.kt

@@ -4,15 +4,17 @@ import android.content.Context
 import androidx.room.Database
 import androidx.room.Room
 import androidx.room.RoomDatabase
+import uk.silverlabs.silverdroid.data.model.InstalledApp
 import uk.silverlabs.silverdroid.data.model.PwaApp
 
 @Database(
-    entities = [PwaApp::class],
-    version = 1,
+    entities = [PwaApp::class, InstalledApp::class],
+    version = 2,
     exportSchema = true
 )
 abstract class PwaDatabase : RoomDatabase() {
     abstract fun pwaAppDao(): PwaAppDao
+    abstract fun installedAppDao(): InstalledAppDao
 
     companion object {
         @Volatile

app/src/main/kotlin/uk/silverlabs/silverdroid/data/model/InstalledApp.kt

@@ -0,0 +1,19 @@
+package uk.silverlabs.silverdroid.data.model
+
+import androidx.room.Entity
+import androidx.room.PrimaryKey
+
+@Entity(tableName = "installed_apps")
+data class InstalledApp(
+    @PrimaryKey(autoGenerate = true) val id: Long = 0,
+    val slug: String,
+    val packageName: String,
+    val appName: String,
+    val installedVersion: String,
+    val installedAt: Long = System.currentTimeMillis(),
+    val hasUpdate: Boolean = false,
+    val pendingVersion: String? = null,
+    val pendingDownloadUrl: String? = null,
+    val pendingsha256: String? = null,
+    val pendingReleaseNotes: String? = null
+)

app/src/main/kotlin/uk/silverlabs/silverdroid/ui/webview/AppStoreJsBridge.kt

@@ -0,0 +1,118 @@
+package uk.silverlabs.silverdroid.ui.webview
+
+import android.content.Context
+import android.content.pm.PackageManager
+import android.util.Log
+import android.webkit.JavascriptInterface
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+import uk.silverlabs.silverdroid.data.PwaDatabase
+import uk.silverlabs.silverdroid.data.model.InstalledApp
+import uk.silverlabs.silverdroid.update.InstallerService
+
+/**
+ * JavascriptInterface exposed to the AppStore Blazor WASM app via window.SilverDROID.
+ *
+ * Usage from JavaScript / Blazor interop:
+ *   window.SilverDROID.installApp(slug, downloadUrl, sha256, appName, version)
+ *   window.SilverDROID.isAppInstalled(packageName)
+ *   window.SilverDROID.getInstalledVersion(slug)
+ *   window.SilverDROID.requestUpdate(slug)
+ */
+class AppStoreJsBridge(
+    private val context: Context,
+    private val scope: CoroutineScope,
+    private val onShowUpdateDialog: (slug: String) -> Unit = {}
+) {
+
+    companion object {
+        private const val TAG = "AppStoreJsBridge"
+        /** Name registered with addJavascriptInterface — window.SilverDROID in the web app */
+        const val BRIDGE_NAME = "SilverDROID"
+    }
+
+    private val installer = InstallerService(context)
+    private val db get() = PwaDatabase.getInstance(context)
+
+    /**
+     * Called by the Blazor WASM app to install an APK natively.
+     * Runs download + verify + PackageInstaller in a coroutine; registers the app in DB on success.
+     */
+    @JavascriptInterface
+    fun installApp(slug: String, downloadUrl: String, sha256: String, appName: String, version: String) {
+        Log.i(TAG, "installApp: slug=$slug version=$version")
+        scope.launch(Dispatchers.IO) {
+            val success = installer.downloadAndInstall(
+                slug = slug,
+                downloadUrl = downloadUrl,
+                sha256 = sha256.ifBlank { null },
+                appName = appName,
+                version = version
+            )
+            if (success) {
+                val existing = db.installedAppDao().getBySlug(slug)
+                if (existing == null) {
+                    db.installedAppDao().insert(
+                        InstalledApp(
+                            slug = slug,
+                            packageName = slugToPackageName(slug),
+                            appName = appName,
+                            installedVersion = version
+                        )
+                    )
+                } else {
+                    db.installedAppDao().markUpdateInstalled(slug, version)
+                }
+                Log.i(TAG, "installApp: DB record saved for $slug")
+            }
+        }
+    }
+
+    /**
+     * Returns true if the given package is installed on this device.
+     * Called synchronously from JS.
+     */
+    @JavascriptInterface
+    fun isAppInstalled(packageName: String): Boolean {
+        return try {
+            context.packageManager.getPackageInfo(packageName, 0)
+            true
+        } catch (_: PackageManager.NameNotFoundException) {
+            false
+        }
+    }
+
+    /**
+     * Returns the installed version string for a slug, or "" if not tracked.
+     * Called synchronously from JS (runs on background thread — safe per Android docs).
+     */
+    @JavascriptInterface
+    fun getInstalledVersion(slug: String): String {
+        return try {
+            kotlinx.coroutines.runBlocking(Dispatchers.IO) {
+                db.installedAppDao().getBySlug(slug)?.installedVersion ?: ""
+            }
+        } catch (e: Exception) {
+            Log.w(TAG, "getInstalledVersion failed for $slug", e)
+            ""
+        }
+    }
+
+    /**
+     * Called by the web app to trigger the native update bottom sheet.
+     * Delegates to the host composable via callback.
+     */
+    @JavascriptInterface
+    fun requestUpdate(slug: String) {
+        Log.i(TAG, "requestUpdate: slug=$slug")
+        scope.launch(Dispatchers.Main) {
+            onShowUpdateDialog(slug)
+        }
+    }
+
+    // Derive a likely package name from a slug; actual name stored by installApp
+    private fun slugToPackageName(slug: String): String =
+        "uk.silverlabs.${slug.replace("-", ".")}"
+}

app/src/main/kotlin/uk/silverlabs/silverdroid/update/InstallStatusReceiver.kt

@@ -0,0 +1,66 @@
+package uk.silverlabs.silverdroid.update
+
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import android.content.pm.PackageInstaller
+import android.util.Log
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+
+/**
+ * Receives install status callbacks from PackageInstaller session commits.
+ * Also listens for PACKAGE_REPLACED to update InstalledApp records.
+ */
+class InstallStatusReceiver : BroadcastReceiver() {
+
+    companion object {
+        private const val TAG = "InstallStatusReceiver"
+    }
+
+    override fun onReceive(context: Context, intent: Intent) {
+        when (intent.action) {
+            "uk.silverlabs.silverdroid.INSTALL_STATUS" -> {
+                val status = intent.getIntExtra(PackageInstaller.EXTRA_STATUS, -1)
+                val msg = intent.getStringExtra(PackageInstaller.EXTRA_STATUS_MESSAGE)
+                when (status) {
+                    PackageInstaller.STATUS_SUCCESS ->
+                        Log.i(TAG, "Package install succeeded")
+                    PackageInstaller.STATUS_FAILURE,
+                    PackageInstaller.STATUS_FAILURE_ABORTED,
+                    PackageInstaller.STATUS_FAILURE_BLOCKED,
+                    PackageInstaller.STATUS_FAILURE_CONFLICT,
+                    PackageInstaller.STATUS_FAILURE_INCOMPATIBLE,
+                    PackageInstaller.STATUS_FAILURE_INVALID,
+                    PackageInstaller.STATUS_FAILURE_STORAGE ->
+                        Log.e(TAG, "Package install failed: status=$status msg=$msg")
+                    PackageInstaller.STATUS_PENDING_USER_ACTION -> {
+                        // Need to prompt user — launch the confirmation intent
+                        val confirmIntent = intent.getParcelableExtra<Intent>(Intent.EXTRA_INTENT)
+                        confirmIntent?.let {
+                            it.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
+                            context.startActivity(it)
+                        }
+                    }
+                }
+            }
+
+            Intent.ACTION_PACKAGE_REPLACED,
+            Intent.ACTION_PACKAGE_ADDED -> {
+                val pkg = intent.data?.schemeSpecificPart ?: return
+                Log.i(TAG, "Package installed/replaced: $pkg")
+                // Update DB — we don't know the new version here, the bridge handles that
+                CoroutineScope(Dispatchers.IO).launch {
+                    val dao = uk.silverlabs.silverdroid.data.PwaDatabase
+                        .getInstance(context).installedAppDao()
+                    val app = dao.getByPackageName(pkg) ?: return@launch
+                    // Clear the pending update flag; version is set by AppStoreJsBridge.installApp
+                    if (app.pendingVersion != null) {
+                        dao.markUpdateInstalled(app.slug, app.pendingVersion)
+                    }
+                }
+            }
+        }
+    }
+}

app/src/main/kotlin/uk/silverlabs/silverdroid/update/InstallerService.kt

@@ -0,0 +1,184 @@
+package uk.silverlabs.silverdroid.update
+
+import android.app.DownloadManager
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import android.content.IntentFilter
+import android.content.pm.PackageInstaller
+import android.net.Uri
+import android.os.Build
+import android.util.Log
+import androidx.core.content.FileProvider
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.suspendCancellableCoroutine
+import kotlinx.coroutines.withContext
+import uk.silverlabs.silverdroid.data.PwaDatabase
+import java.io.File
+import java.io.FileInputStream
+import java.security.MessageDigest
+import kotlin.coroutines.resume
+
+class InstallerService(private val context: Context) {
+
+    companion object {
+        private const val TAG = "InstallerService"
+        const val FILE_PROVIDER_AUTHORITY = "uk.silverlabs.silverdroid.fileprovider"
+    }
+
+    /**
+     * Download APK, verify SHA-256, then install via PackageInstaller session API.
+     * Returns true if install session was created successfully (actual install is user-confirmed).
+     */
+    suspend fun downloadAndInstall(
+        slug: String,
+        downloadUrl: String,
+        sha256: String?,
+        appName: String,
+        version: String,
+        onProgress: (Int) -> Unit = {}
+    ): Boolean = withContext(Dispatchers.IO) {
+        try {
+            val apkFile = downloadApk(downloadUrl, slug, appName, onProgress)
+                ?: return@withContext false
+
+            if (sha256 != null && !verifySha256(apkFile, sha256)) {
+                Log.e(TAG, "SHA-256 verification failed for $slug")
+                apkFile.delete()
+                return@withContext false
+            }
+
+            installApk(apkFile)
+            true
+        } catch (e: Exception) {
+            Log.e(TAG, "Failed to download/install $slug", e)
+            false
+        }
+    }
+
+    private suspend fun downloadApk(
+        url: String,
+        slug: String,
+        appName: String,
+        onProgress: (Int) -> Unit
+    ): File? = suspendCancellableCoroutine { cont ->
+        val cacheDir = context.externalCacheDir ?: context.cacheDir
+        val apkFile = File(cacheDir, "$slug.apk")
+
+        val request = DownloadManager.Request(Uri.parse(url)).apply {
+            setTitle("Downloading $appName")
+            setDescription("Preparing update...")
+            setDestinationUri(Uri.fromFile(apkFile))
+            setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE)
+            setAllowedOverMetered(true)
+            setAllowedOverRoaming(false)
+        }
+
+        val dm = context.getSystemService(Context.DOWNLOAD_SERVICE) as DownloadManager
+        val downloadId = dm.enqueue(request)
+
+        // Poll for completion
+        val receiver = object : BroadcastReceiver() {
+            override fun onReceive(ctx: Context, intent: Intent) {
+                val id = intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, -1)
+                if (id != downloadId) return
+
+                context.unregisterReceiver(this)
+
+                val query = DownloadManager.Query().setFilterById(downloadId)
+                val cursor = dm.query(query)
+                if (cursor.moveToFirst()) {
+                    val statusCol = cursor.getColumnIndex(DownloadManager.COLUMN_STATUS)
+                    val status = cursor.getInt(statusCol)
+                    cursor.close()
+                    if (status == DownloadManager.STATUS_SUCCESSFUL) {
+                        onProgress(100)
+                        cont.resume(apkFile)
+                    } else {
+                        cont.resume(null)
+                    }
+                } else {
+                    cursor.close()
+                    cont.resume(null)
+                }
+            }
+        }
+
+        context.registerReceiver(
+            receiver,
+            IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE),
+            Context.RECEIVER_NOT_EXPORTED
+        )
+
+        cont.invokeOnCancellation {
+            dm.remove(downloadId)
+            try { context.unregisterReceiver(receiver) } catch (_: Exception) {}
+        }
+    }
+
+    private fun verifySha256(file: File, expectedHex: String): Boolean {
+        val digest = MessageDigest.getInstance("SHA-256")
+        FileInputStream(file).use { fis ->
+            val buf = ByteArray(8192)
+            var read: Int
+            while (fis.read(buf).also { read = it } != -1) {
+                digest.update(buf, 0, read)
+            }
+        }
+        val actualHex = digest.digest().joinToString("") { "%02x".format(it) }
+        return actualHex.equals(expectedHex, ignoreCase = true)
+    }
+
+    private fun installApk(apkFile: File) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+            installViaPackageInstaller(apkFile)
+        } else {
+            installViaIntent(apkFile)
+        }
+    }
+
+    private fun installViaPackageInstaller(apkFile: File) {
+        val pi = context.packageManager.packageInstaller
+        val params = PackageInstaller.SessionParams(PackageInstaller.SessionParams.MODE_FULL_INSTALL)
+        params.setSize(apkFile.length())
+
+        val sessionId = pi.createSession(params)
+        val session = pi.openSession(sessionId)
+
+        FileInputStream(apkFile).use { fis ->
+            session.openWrite("package", 0, apkFile.length()).use { os ->
+                fis.copyTo(os)
+                session.fsync(os)
+            }
+        }
+
+        val intent = Intent(context, InstallStatusReceiver::class.java).apply {
+            action = "uk.silverlabs.silverdroid.INSTALL_STATUS"
+        }
+        val pi2 = android.app.PendingIntent.getBroadcast(
+            context, sessionId, intent,
+            android.app.PendingIntent.FLAG_UPDATE_CURRENT or android.app.PendingIntent.FLAG_MUTABLE
+        )
+        session.commit(pi2.intentSender)
+        session.close()
+    }
+
+    private fun installViaIntent(apkFile: File) {
+        val apkUri = FileProvider.getUriForFile(context, FILE_PROVIDER_AUTHORITY, apkFile)
+        val intent = Intent(Intent.ACTION_VIEW).apply {
+            setDataAndType(apkUri, "application/vnd.android.package-archive")
+            flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_GRANT_READ_URI_PERMISSION
+        }
+        context.startActivity(intent)
+    }
+
+    /**
+     * Mark app as successfully updated in the DB after PACKAGE_REPLACED broadcast.
+     */
+    suspend fun onPackageInstalled(packageName: String, newVersion: String) {
+        val dao = PwaDatabase.getInstance(context).installedAppDao()
+        val app = dao.getByPackageName(packageName) ?: return
+        dao.markUpdateInstalled(app.slug, newVersion)
+        Log.i(TAG, "Updated DB record for ${app.slug} to $newVersion")
+    }
+}

app/src/main/kotlin/uk/silverlabs/silverdroid/update/UpdateCheckResponseDto.kt

@@ -0,0 +1,12 @@
+package uk.silverlabs.silverdroid.update
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class UpdateCheckResponseDto(
+    val hasUpdate: Boolean,
+    val latestVersion: String,
+    val downloadUrl: String? = null,
+    val sha256: String? = null,
+    val releaseNotes: String? = null
+)

app/src/main/kotlin/uk/silverlabs/silverdroid/update/UpdateCheckerWorker.kt

@@ -0,0 +1,137 @@
+package uk.silverlabs.silverdroid.update
+
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.app.PendingIntent
+import android.content.Context
+import android.content.Intent
+import android.os.Build
+import android.util.Log
+import androidx.core.app.NotificationCompat
+import androidx.work.CoroutineWorker
+import androidx.work.WorkerParameters
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import kotlinx.serialization.json.Json
+import uk.silverlabs.silverdroid.MainActivity
+import uk.silverlabs.silverdroid.R
+import uk.silverlabs.silverdroid.data.PwaDatabase
+import uk.silverlabs.silverdroid.data.model.InstalledApp
+import java.net.HttpURLConnection
+import java.net.URL
+
+class UpdateCheckerWorker(
+    private val context: Context,
+    params: WorkerParameters
+) : CoroutineWorker(context, params) {
+
+    companion object {
+        const val WORK_NAME = "silverdroid_update_checker"
+        const val NOTIFICATION_CHANNEL_ID = "app-updates"
+        private const val TAG = "UpdateCheckerWorker"
+        private const val NOTIFICATION_ID = 1001
+
+        fun createNotificationChannel(context: Context) {
+            val channel = NotificationChannel(
+                NOTIFICATION_CHANNEL_ID,
+                "App Updates",
+                NotificationManager.IMPORTANCE_DEFAULT
+            ).apply {
+                description = "Notifications for available app updates from SilverSHELL AppStore"
+            }
+            val nm = context.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
+            nm.createNotificationChannel(channel)
+        }
+    }
+
+    private val json = Json { ignoreUnknownKeys = true }
+
+    override suspend fun doWork(): Result = withContext(Dispatchers.IO) {
+        try {
+            val dao = PwaDatabase.getInstance(context).installedAppDao()
+            val installedApps = dao.getAllAppsOnce()
+
+            if (installedApps.isEmpty()) return@withContext Result.success()
+
+            val updatesFound = mutableListOf<InstalledApp>()
+
+            for (app in installedApps) {
+                try {
+                    val response = checkUpdate(app.slug, app.installedVersion)
+                    if (response?.hasUpdate == true) {
+                        val updated = app.copy(
+                            hasUpdate = true,
+                            pendingVersion = response.latestVersion,
+                            pendingDownloadUrl = response.downloadUrl,
+                            pendingsha256 = response.sha256,
+                            pendingReleaseNotes = response.releaseNotes
+                        )
+                        dao.update(updated)
+                        updatesFound.add(updated)
+                    }
+                } catch (e: Exception) {
+                    Log.w(TAG, "Failed to check update for ${app.slug}", e)
+                }
+            }
+
+            if (updatesFound.isNotEmpty()) {
+                fireUpdateNotification(updatesFound)
+            }
+
+            Result.success()
+        } catch (e: Exception) {
+            Log.e(TAG, "UpdateCheckerWorker failed", e)
+            Result.retry()
+        }
+    }
+
+    private fun checkUpdate(slug: String, currentVersion: String): UpdateCheckResponseDto? {
+        val url = URL("https://store.silverlabs.uk/api/apps/$slug/check-update?platform=Android&version=$currentVersion")
+        val conn = url.openConnection() as HttpURLConnection
+        return try {
+            conn.connectTimeout = 15_000
+            conn.readTimeout = 15_000
+            conn.requestMethod = "GET"
+            if (conn.responseCode == 200) {
+                val body = conn.inputStream.bufferedReader().readText()
+                json.decodeFromString<UpdateCheckResponseDto>(body)
+            } else null
+        } finally {
+            conn.disconnect()
+        }
+    }
+
+    private fun fireUpdateNotification(updates: List<InstalledApp>) {
+        val nm = context.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
+
+        val intent = Intent(context, MainActivity::class.java).apply {
+            flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK
+        }
+        val pendingIntent = PendingIntent.getActivity(
+            context, 0, intent,
+            PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE
+        )
+
+        val title = if (updates.size == 1) {
+            "${updates[0].appName} update available"
+        } else {
+            "${updates.size} app updates available"
+        }
+        val body = if (updates.size == 1) {
+            "Version ${updates[0].pendingVersion} is ready to install"
+        } else {
+            updates.joinToString(", ") { it.appName }
+        }
+
+        val notification = NotificationCompat.Builder(context, NOTIFICATION_CHANNEL_ID)
+            .setSmallIcon(android.R.drawable.stat_sys_download_done)
+            .setContentTitle(title)
+            .setContentText(body)
+            .setPriority(NotificationCompat.PRIORITY_DEFAULT)
+            .setContentIntent(pendingIntent)
+            .setAutoCancel(true)
+            .build()
+
+        nm.notify(NOTIFICATION_ID, notification)
+    }
+}

app/src/main/res/xml/file_paths.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<paths>
+    <!-- External cache dir — APKs downloaded by InstallerService -->
+    <external-cache-path name="apk_downloads" path="." />
+    <!-- Fallback to internal cache if external storage unavailable -->
+    <cache-path name="apk_downloads_internal" path="." />
+</paths>