android/app/src/main/AndroidManifest.xml

@@ -8,7 +8,16 @@
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE_MEDIA_PLAYBACK" />
     <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
+    <!-- In-app self-update. REQUEST_INSTALL_PACKAGES lets us hand an APK to the
+         platform installer at all; UPDATE_PACKAGES_WITHOUT_USER_ACTION (API 31+)
+         is what lets that install happen with NO confirm dialog. The platform
+         grants the silent path only when the installer opts in via
+         SessionParams.setRequireUserAction(USER_ACTION_NOT_REQUIRED), the
+         installed app targets API 29+, the installer holds this permission, and
+         the target is the installer itself — all true here, since Minstrel is
+         updating Minstrel. See update/data/SelfUpdateSession.kt. -->
     <uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES" />
+    <uses-permission android:name="android.permission.UPDATE_PACKAGES_WITHOUT_USER_ACTION" />
     <uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
     <uses-permission android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE" />
 
@@ -48,15 +57,11 @@
             </intent-filter>
         </service>
 
-        <provider
-            android:name="androidx.core.content.FileProvider"
-            android:authorities="${applicationId}.fileprovider"
-            android:exported="false"
-            android:grantUriPermissions="true">
-            <meta-data
-                android:name="android.support.FILE_PROVIDER_PATHS"
-                android:resource="@xml/file_paths" />
-        </provider>
+        <!-- The FileProvider that used to live here existed solely to expose the
+             downloaded update APK as a content:// URI for the old ACTION_VIEW
+             install intent. A PackageInstaller session takes a stream instead,
+             so both the provider and res/xml/file_paths.xml are gone — nothing
+             else in the app ever used that authority. -->
 
         <!-- On-demand WorkManager initialization: MinstrelApplication
              implements Configuration.Provider and supplies the

android/app/src/main/java/com/fabledsword/minstrel/settings/ui/AboutCardViewModel.kt

@@ -6,22 +6,27 @@ import com.fabledsword.minstrel.BuildConfig
 import com.fabledsword.minstrel.api.ErrorCopy
 import com.fabledsword.minstrel.models.UpdateInfo
 import com.fabledsword.minstrel.update.data.ApkInstaller
+import com.fabledsword.minstrel.update.data.InstallStage
 import com.fabledsword.minstrel.update.data.UpdateRepository
+import com.fabledsword.minstrel.update.data.isBusy
 import com.fabledsword.minstrel.update.data.isVersionNewer
+import com.fabledsword.minstrel.update.data.message
+import com.fabledsword.minstrel.update.data.stage
 import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
+import java.io.File
 import javax.inject.Inject
 
 /**
  * One of three terminal states the Check-for-updates button surfaces.
  * `Idle` is the pre-check state; `Latest` means the installed build
  * matches or exceeds the server's bundled APK; `UpdateAvailable`
- * surfaces an "Install vX.Y.Z" button that downloads + launches the
- * system installer via [ApkInstaller].
+ * surfaces an "Install vX.Y.Z" button that downloads the APK and
+ * installs it via [ApkInstaller].
  */
 sealed interface UpdateCheckResult {
     data object Idle : UpdateCheckResult
@@ -33,7 +38,7 @@ sealed interface UpdateCheckResult {
 data class AboutUiState(
     val installedVersion: String = BuildConfig.VERSION_NAME,
     val isChecking: Boolean = false,
-    val isInstalling: Boolean = false,
+    val installStage: InstallStage = InstallStage.IDLE,
     val installMessage: String? = null,
     val result: UpdateCheckResult = UpdateCheckResult.Idle,
 )
@@ -43,9 +48,9 @@ data class AboutUiState(
  * [UpdateRepository.getLatest], compares versus the build's
  * VERSION_NAME via [isVersionNewer], and reports the terminal state.
  * When an update is available, [install] downloads the APK via
- * [ApkInstaller] and hands it to the system installer — routing the
- * user to the "install unknown apps" settings page first when that
- * permission hasn't been granted.
+ * [ApkInstaller] and installs it — routing the user to the "install
+ * unknown apps" settings page first when that permission hasn't been
+ * granted.
  */
 @HiltViewModel
 class AboutCardViewModel @Inject constructor(
@@ -75,7 +80,7 @@ class AboutCardViewModel @Inject constructor(
     }
 
     fun install(info: UpdateInfo) {
-        if (internal.value.isInstalling) return
+        if (internal.value.installStage.isBusy()) return
         if (!installer.canInstall()) {
             installer.requestInstallPermission()
             internal.update {
@@ -84,21 +89,32 @@ class AboutCardViewModel @Inject constructor(
             return
         }
         viewModelScope.launch {
-            internal.update { it.copy(isInstalling = true, installMessage = null) }
-            runCatching { installer.downloadApk(info.apkUrl) }
-                .onSuccess { apk ->
-                    installer.launchInstall(apk)
-                    internal.update { it.copy(isInstalling = false) }
-                }
-                .onFailure { e ->
-                    val why = ErrorCopy.fromThrowable(e)
-                    internal.update {
-                        it.copy(
-                            isInstalling = false,
-                            installMessage = "Couldn't download update: $why",
-                        )
-                    }
+            internal.update {
+                it.copy(installStage = InstallStage.DOWNLOADING, installMessage = null)
+            }
+            val apk = download(info.apkUrl)
+            if (apk != null) {
+                // The install half now suspends on the platform's verdict, so it
+                // gets its own stage — reporting "Downloading…" through it would
+                // be a lie once a confirm dialog is on screen.
+                internal.update { it.copy(installStage = InstallStage.INSTALLING) }
+                val outcome = installer.install(apk)
+                internal.update {
+                    it.copy(installStage = outcome.stage(), installMessage = outcome.message())
                 }
+            }
         }
     }
+
+    private suspend fun download(apkUrl: String): File? =
+        runCatching { installer.downloadApk(apkUrl) }
+            .onFailure { e ->
+                internal.update {
+                    it.copy(
+                        installStage = InstallStage.ERROR,
+                        installMessage = "Couldn't download update: ${ErrorCopy.fromThrowable(e)}",
+                    )
+                }
+            }
+            .getOrNull()
 }

android/app/src/main/java/com/fabledsword/minstrel/settings/ui/SettingsScreen.kt

@@ -58,6 +58,8 @@ import com.fabledsword.minstrel.nav.ServerUrl
 import com.fabledsword.minstrel.shared.widgets.MinstrelTopAppBar
 import com.fabledsword.minstrel.theme.ThemeMode
 import com.fabledsword.minstrel.theme.ThemePreferenceViewModel
+import com.fabledsword.minstrel.update.data.InstallStage
+import com.fabledsword.minstrel.update.data.isBusy
 
 @Composable
 fun SettingsScreen(
@@ -381,7 +383,7 @@ private fun UpdateControls(state: AboutUiState, viewModel: AboutCardViewModel) {
     UpdateCheckLine(result = state.result)
     Button(
         onClick = viewModel::checkForUpdates,
-        enabled = !state.isChecking && !state.isInstalling,
+        enabled = !state.isChecking && !state.installStage.isBusy(),
         modifier = Modifier.fillMaxWidth(),
     ) {
         if (state.isChecking) {
@@ -393,7 +395,7 @@ private fun UpdateControls(state: AboutUiState, viewModel: AboutCardViewModel) {
     if (available != null) {
         InstallButton(
             version = available.info.version,
-            isInstalling = state.isInstalling,
+            stage = state.installStage,
             onClick = { viewModel.install(available.info) },
         )
     }
@@ -407,16 +409,22 @@ private fun UpdateControls(state: AboutUiState, viewModel: AboutCardViewModel) {
 }
 
 @Composable
-private fun InstallButton(version: String, isInstalling: Boolean, onClick: () -> Unit) {
+private fun InstallButton(version: String, stage: InstallStage, onClick: () -> Unit) {
     Button(
         onClick = onClick,
-        enabled = !isInstalling,
+        enabled = !stage.isBusy(),
         modifier = Modifier.fillMaxWidth(),
     ) {
-        if (isInstalling) {
+        if (stage.isBusy()) {
             ButtonSpinner()
         }
-        Text(if (isInstalling) "Downloading…" else "Install $version")
+        Text(
+            when (stage) {
+                InstallStage.DOWNLOADING -> "Downloading…"
+                InstallStage.INSTALLING -> "Installing…"
+                else -> "Install $version"
+            },
+        )
     }
 }
 

android/app/src/main/java/com/fabledsword/minstrel/update/data/ApkInstaller.kt

@@ -5,7 +5,6 @@ import android.content.Intent
 import android.net.Uri
 import android.os.Build
 import android.provider.Settings
-import androidx.core.content.FileProvider
 import dagger.hilt.android.qualifiers.ApplicationContext
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
@@ -17,27 +16,26 @@ import javax.inject.Inject
 import javax.inject.Singleton
 
 private const val APK_FILENAME = "minstrel-update.apk"
-private const val APK_MIME = "application/vnd.android.package-archive"
 
 /**
- * Downloads the server-bundled APK and hands it to Android's package
- * installer. Mirrors Flutter's `update/installer.dart` — the native
- * side that the Flutter MethodChannel delegated to.
+ * Downloads the server-bundled APK and installs it over ourselves.
  *
  * The download goes through the shared [OkHttpClient] so it inherits
  * the auth cookie + the BaseUrlInterceptor host rewrite (apkUrl is
  * server-relative, e.g. `/api/client/apk`). The APK lands in the
- * cache dir, exposed to the system installer via the app's
- * FileProvider content:// URI.
+ * cache dir; [SelfUpdateSession] streams it from there into a
+ * [android.content.pm.PackageInstaller] session.
  *
  * On Android O+ the user must have granted "install unknown apps"
  * for Minstrel; [canInstall] reports it and [requestInstallPermission]
- * opens the relevant settings screen.
+ * opens the relevant settings screen. That grant is still required with
+ * the session API — silent *updates* don't imply silent *permission*.
  */
 @Singleton
 class ApkInstaller @Inject constructor(
     @ApplicationContext private val context: Context,
     private val okHttpClient: OkHttpClient,
+    private val session: SelfUpdateSession,
 ) {
     suspend fun downloadApk(apkUrl: String): File = withContext(Dispatchers.IO) {
         val request = Request.Builder()
@@ -61,19 +59,13 @@ class ApkInstaller @Inject constructor(
         Build.VERSION.SDK_INT < Build.VERSION_CODES.O ||
             context.packageManager.canRequestPackageInstalls()
 
-    /** Hand the downloaded APK to the system installer's confirm dialog. */
-    fun launchInstall(apk: File) {
-        val uri: Uri = FileProvider.getUriForFile(
-            context,
-            "${context.packageName}.fileprovider",
-            apk,
-        )
-        val intent = Intent(Intent.ACTION_VIEW).apply {
-            setDataAndType(uri, APK_MIME)
-            addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION or Intent.FLAG_ACTIVITY_NEW_TASK)
-        }
-        context.startActivity(intent)
-    }
+    /**
+     * Install [apk] over ourselves, suspending until the platform decides.
+     *
+     * Note for callers: on a successful silent install this never returns —
+     * the process is replaced. Don't treat the absence of a verdict as failure.
+     */
+    suspend fun install(apk: File): InstallOutcome = session.run(apk)
 
     /** Open the "install unknown apps" settings page for Minstrel. */
     fun requestInstallPermission() {

android/app/src/main/java/com/fabledsword/minstrel/update/data/InstallOutcome.kt

@@ -0,0 +1,68 @@
+package com.fabledsword.minstrel.update.data
+
+/**
+ * Terminal verdict from the platform on a self-update install (#2438).
+ *
+ * The old `ACTION_VIEW` handoff had no verdict at all — we fired an intent and
+ * assumed. A [PackageInstaller][android.content.pm.PackageInstaller] session
+ * reports back, so "declined" and "failed" stop looking identical.
+ */
+sealed interface InstallOutcome {
+    /**
+     * The platform completed the install.
+     *
+     * Rarely observed on a self-update: our process is replaced the moment the
+     * new APK lands, so the coroutine awaiting this usually dies before it
+     * resumes. Modelled anyway — silently relying on being killed would make
+     * the success path invisible to anyone reading this.
+     */
+    data object Installed : InstallOutcome
+
+    /** The user declined the platform's confirm dialog. Not an error. */
+    data object Cancelled : InstallOutcome
+
+    /** The platform refused. [reason] is its own message, where it gave one. */
+    data class Failed(val reason: String?) : InstallOutcome
+}
+
+/**
+ * Where an install has got to, for the two surfaces that show it: the shell's
+ * [UpdateBanner][com.fabledsword.minstrel.update.ui.UpdateBanner] and the
+ * Settings About card.
+ *
+ * DOWNLOADING and INSTALLING are deliberately distinct. They used to be one
+ * state because the install half was fire-and-forget and took no time from our
+ * side; now that we await the platform's verdict, collapsing them would leave
+ * the UI claiming "Downloading…" through an install that can sit on a confirm
+ * dialog indefinitely.
+ */
+enum class InstallStage { IDLE, DOWNLOADING, INSTALLING, ERROR }
+
+/** True while an install is underway and a second tap should do nothing. */
+fun InstallStage.isBusy(): Boolean =
+    this == InstallStage.DOWNLOADING || this == InstallStage.INSTALLING
+
+/**
+ * The stage an outcome lands the UI in. A cancelled install returns to IDLE
+ * rather than ERROR — the user chose it, so presenting it as a failure would
+ * be a lie with a red tint.
+ */
+fun InstallOutcome.stage(): InstallStage = when (this) {
+    InstallOutcome.Installed, InstallOutcome.Cancelled -> InstallStage.IDLE
+    is InstallOutcome.Failed -> InstallStage.ERROR
+}
+
+/**
+ * User-facing copy for an outcome; null when there is nothing worth saying.
+ *
+ * Lives beside the outcome rather than in either UI package because two
+ * separate screens surface the same verdicts and must not drift — the same
+ * reasoning that puts [ErrorCopy][com.fabledsword.minstrel.api.ErrorCopy]
+ * outside the UI layer.
+ */
+fun InstallOutcome.message(): String? = when (this) {
+    InstallOutcome.Installed -> null
+    InstallOutcome.Cancelled -> "Update cancelled."
+    is InstallOutcome.Failed -> reason?.let { "Couldn't install update: $it" }
+        ?: "Couldn't install update."
+}

android/app/src/main/java/com/fabledsword/minstrel/update/data/SelfUpdateSession.kt

@@ -0,0 +1,220 @@
+package com.fabledsword.minstrel.update.data
+
+import android.app.PendingIntent
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import android.content.IntentFilter
+import android.content.IntentSender
+import android.content.pm.ApplicationInfo
+import android.content.pm.PackageInstaller
+import android.content.pm.PackageManager
+import android.os.Build
+import androidx.core.content.ContextCompat
+import androidx.core.content.IntentCompat
+import dagger.hilt.android.qualifiers.ApplicationContext
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.suspendCancellableCoroutine
+import kotlinx.coroutines.withContext
+import java.io.File
+import javax.inject.Inject
+import javax.inject.Singleton
+import kotlin.coroutines.resume
+
+private const val STAGED_APK_NAME = "minstrel-update"
+
+/** Whole-file write: openWrite takes a Long offset, and Kotlin won't widen 0. */
+private const val WRITE_FROM_START = 0L
+
+/** Our own broadcast, delivered by the platform via the session's IntentSender. */
+private const val RESULT_ACTION = "com.fabledsword.minstrel.INSTALL_RESULT"
+
+/**
+ * Installs an APK over ourselves through a [PackageInstaller] session (#2438).
+ *
+ * Split from [ApkInstaller] because the two halves are different work — one
+ * speaks HTTP, the other speaks to the package manager — and the session half
+ * carries a receiver, a PendingIntent and version-gated params that would
+ * crowd the downloader out of its own file.
+ *
+ * ## Why a session, rather than the ACTION_VIEW intent this replaced
+ *
+ * Two reasons, and the second is the one that matters to users.
+ *
+ * The old path fired `ACTION_VIEW` at an `application/vnd.android.package-archive`
+ * URI and hoped. It could not report an outcome, so a failed install and a
+ * user who declined looked identical — see [InstallOutcome].
+ *
+ * More importantly, a session is where the platform lets a self-updater say it
+ * is one. [PackageInstaller.SessionParams.setRequireUserAction] with
+ * `USER_ACTION_NOT_REQUIRED`, paired with the `UPDATE_PACKAGES_WITHOUT_USER_ACTION`
+ * manifest permission, is the sanctioned way to update with **no dialog at
+ * all**. The platform grants that when all of: the installer opts in (here),
+ * the installed app targets API 29+ (we're on 36), the installer holds the
+ * permission (we do), and the target is the installer itself or something it
+ * first installed (we are updating ourselves). All four hold.
+ *
+ * ## What is deliberately absent
+ *
+ * No `setRequestUpdateOwnership(true)`. It reads like the right declaration for
+ * a self-updater and it is not: ownership can only be claimed on **initial**
+ * installation — setting it on an update is documented as a no-op — and it also
+ * wants the privileged `ENFORCE_UPDATE_OWNERSHIP` permission. It exists for app
+ * stores claiming the apps they install, not for an app updating itself.
+ */
+@Singleton
+class SelfUpdateSession @Inject constructor(
+    @ApplicationContext private val context: Context,
+) {
+    /**
+     * Stage [apk] and hand it to the platform, suspending until a terminal
+     * verdict arrives.
+     *
+     * Never returns on the happy path when the install is silent: the platform
+     * replaces this process the moment the new APK lands, so the coroutine dies
+     * rather than resuming. Callers must treat that as success, not a hang.
+     */
+    suspend fun run(apk: File): InstallOutcome {
+        val staged = withContext(Dispatchers.IO) { runCatching { stage(apk) } }
+        return staged.fold(
+            onSuccess = { sessionId -> awaitCommit(sessionId) },
+            onFailure = { InstallOutcome.Failed(it.message) },
+        )
+    }
+
+    /** Open a session, stream the APK in, return the session id. */
+    private fun stage(apk: File): Int {
+        val installer = context.packageManager.packageInstaller
+        val sessionId = installer.createSession(newParams())
+        installer.openSession(sessionId).use { session ->
+            session.openWrite(STAGED_APK_NAME, WRITE_FROM_START, apk.length()).use { sink ->
+                apk.inputStream().use { source -> source.copyTo(sink) }
+                // fsync before the session closes: the platform validates the
+                // staged bytes at commit, and buffered tail bytes read as a
+                // truncated APK.
+                session.fsync(sink)
+            }
+        }
+        return sessionId
+    }
+
+    // Explicit `params.` receivers rather than an apply {} block: lintVitalRelease
+    // runs on assembleRelease, and NewApi is easier for it to reason about when
+    // the guarded call has a named receiver instead of an implicit one.
+    private fun newParams(): PackageInstaller.SessionParams {
+        val params = PackageInstaller.SessionParams(
+            PackageInstaller.SessionParams.MODE_FULL_INSTALL,
+        )
+        params.setAppPackageName(context.packageName)
+        params.setInstallReason(PackageManager.INSTALL_REASON_USER)
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
+            // The whole point of this class. Pre-S there is no such API, so the
+            // confirm dialog is unavoidable there — degrade, don't fail.
+            params.setRequireUserAction(PackageInstaller.SessionParams.USER_ACTION_NOT_REQUIRED)
+        }
+        return params
+    }
+
+    /**
+     * Commit the session and wait for the platform to report back.
+     *
+     * A pending-user-action status is *not* terminal — the platform is asking us
+     * to show its dialog, and the real verdict arrives in a second broadcast
+     * once the user decides. So the receiver stays registered across it.
+     */
+    private suspend fun awaitCommit(sessionId: Int): InstallOutcome =
+        suspendCancellableCoroutine { continuation ->
+            val installer = context.packageManager.packageInstaller
+            val receiver = object : BroadcastReceiver() {
+                override fun onReceive(unused: Context, intent: Intent) {
+                    val status = intent.getIntExtra(
+                        PackageInstaller.EXTRA_STATUS,
+                        PackageInstaller.STATUS_FAILURE,
+                    )
+                    if (status == PackageInstaller.STATUS_PENDING_USER_ACTION) {
+                        confirmWithUser(intent)
+                    } else {
+                        context.unregisterReceiver(this)
+                        val why = intent.getStringExtra(PackageInstaller.EXTRA_STATUS_MESSAGE)
+                        if (continuation.isActive) continuation.resume(outcomeOf(status, why))
+                    }
+                }
+            }
+            ContextCompat.registerReceiver(
+                context,
+                receiver,
+                IntentFilter(RESULT_ACTION),
+                ContextCompat.RECEIVER_NOT_EXPORTED,
+            )
+            continuation.invokeOnCancellation {
+                // Stop listening, but deliberately do NOT abandon the session.
+                // Cancellation here means our caller's scope died — the user
+                // navigated away, or the VM cleared — and by this point the
+                // session is already committed. The user asked for this install;
+                // killing it because nobody is watching the banner any more
+                // would be the wrong reading of their intent.
+                runCatching { context.unregisterReceiver(receiver) }
+            }
+            runCatching {
+                installer.openSession(sessionId).use { it.commit(resultSender(sessionId)) }
+            }.onFailure { error ->
+                // Resuming normally means invokeOnCancellation never fires, so
+                // clean up the staged session here or it sits until it expires.
+                runCatching { context.unregisterReceiver(receiver) }
+                runCatching { installer.abandonSession(sessionId) }
+                if (continuation.isActive) {
+                    continuation.resume(InstallOutcome.Failed(error.message))
+                }
+            }
+        }
+
+    private fun resultSender(sessionId: Int): IntentSender {
+        // Scoped to our own package so the broadcast can't be answered elsewhere.
+        val intent = Intent(RESULT_ACTION).setPackage(context.packageName)
+        var flags = PendingIntent.FLAG_UPDATE_CURRENT
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
+            // The platform writes its status extras into this intent, so it has
+            // to stay mutable — FLAG_IMMUTABLE would arrive with none of them.
+            flags = flags or PendingIntent.FLAG_MUTABLE
+        }
+        // Session id as the request code keeps concurrent sessions from
+        // colliding on FLAG_UPDATE_CURRENT.
+        return PendingIntent.getBroadcast(context, sessionId, intent, flags).intentSender
+    }
+
+    /**
+     * Show the platform's own confirm dialog, which arrives as an extra.
+     *
+     * The system-app check is not ceremony. Below API 34 a dynamically
+     * registered receiver cannot declare itself unexported, so another app on
+     * the device can broadcast [RESULT_ACTION] at us — and calling
+     * `startActivity` on an attacker-supplied extra would hand it whatever we
+     * can reach. The genuine confirm activity belongs to the platform
+     * installer, so demanding a system component costs the real path nothing.
+     */
+    private fun confirmWithUser(result: Intent) {
+        val pending = IntentCompat.getParcelableExtra(
+            result,
+            Intent.EXTRA_INTENT,
+            Intent::class.java,
+        ) ?: return
+        if (isPlatformActivity(pending)) {
+            context.startActivity(pending.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK))
+        }
+    }
+
+    private fun isPlatformActivity(intent: Intent): Boolean {
+        val flags = intent.resolveActivityInfo(context.packageManager, 0)
+            ?.applicationInfo
+            ?.flags
+            ?: 0
+        val systemFlags = ApplicationInfo.FLAG_SYSTEM or ApplicationInfo.FLAG_UPDATED_SYSTEM_APP
+        return (flags and systemFlags) != 0
+    }
+
+    private fun outcomeOf(status: Int, message: String?): InstallOutcome = when (status) {
+        PackageInstaller.STATUS_SUCCESS -> InstallOutcome.Installed
+        PackageInstaller.STATUS_FAILURE_ABORTED -> InstallOutcome.Cancelled
+        else -> InstallOutcome.Failed(message)
+    }
+}

android/app/src/main/java/com/fabledsword/minstrel/update/ui/UpdateBanner.kt

@@ -28,6 +28,8 @@ import com.composables.icons.lucide.Download
 import com.composables.icons.lucide.Lucide
 import com.composables.icons.lucide.X
 import com.fabledsword.minstrel.models.UpdateInfo
+import com.fabledsword.minstrel.update.data.InstallStage
+import com.fabledsword.minstrel.update.data.isBusy
 
 /**
  * Shell-level soft banner that nudges an available update. Renders
@@ -79,7 +81,7 @@ private fun BannerBody(
             .padding(start = 16.dp, top = 8.dp, end = 4.dp, bottom = 8.dp),
     ) {
         BannerRow(info = info, stage = stage, onInstall = onInstall, onDismiss = onDismiss)
-        if (stage == InstallStage.DOWNLOADING) {
+        if (stage.isBusy()) {
             LinearProgressIndicator(
                 modifier = Modifier
                     .fillMaxWidth()
@@ -124,8 +126,17 @@ private fun BannerRow(
             color = MaterialTheme.colorScheme.onSurfaceVariant,
             modifier = Modifier.weight(1f),
         )
-        TextButton(onClick = onInstall, enabled = stage != InstallStage.DOWNLOADING) {
-            Text(if (stage == InstallStage.DOWNLOADING) "Installing…" else "Install")
+        TextButton(onClick = onInstall, enabled = !stage.isBusy()) {
+            // Downloading and installing are separate words because they're now
+            // separate waits — the install half suspends on the platform, which
+            // may be sitting on a confirm dialog.
+            Text(
+                when (stage) {
+                    InstallStage.DOWNLOADING -> "Downloading…"
+                    InstallStage.INSTALLING -> "Installing…"
+                    else -> "Install"
+                },
+            )
         }
         IconButton(onClick = onDismiss) {
             Icon(

android/app/src/main/java/com/fabledsword/minstrel/update/ui/UpdateBannerViewModel.kt

@@ -5,7 +5,11 @@ import androidx.lifecycle.viewModelScope
 import com.fabledsword.minstrel.api.ErrorCopy
 import com.fabledsword.minstrel.models.UpdateInfo
 import com.fabledsword.minstrel.update.data.ApkInstaller
+import com.fabledsword.minstrel.update.data.InstallStage
 import com.fabledsword.minstrel.update.data.UpdateBannerController
+import com.fabledsword.minstrel.update.data.isBusy
+import com.fabledsword.minstrel.update.data.message
+import com.fabledsword.minstrel.update.data.stage
 import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharingStarted
@@ -13,13 +17,11 @@ import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
+import java.io.File
 import javax.inject.Inject
 
 private const val SHARE_STOP_TIMEOUT_MS = 5_000L
 
-/** Install lifecycle for the banner's Install button. */
-enum class InstallStage { IDLE, DOWNLOADING, ERROR }
-
 data class UpdateBannerUiState(
     val info: UpdateInfo? = null,
     val stage: InstallStage = InstallStage.IDLE,
@@ -28,9 +30,9 @@ data class UpdateBannerUiState(
 
 /**
  * Thin VM over [UpdateBannerController]. Surfaces the available update
- * and runs the download → system-install handoff via [ApkInstaller],
- * mirroring the About card's flow (route to "install unknown apps"
- * settings first when the permission is missing).
+ * and runs the download → install handoff via [ApkInstaller], mirroring
+ * the About card's flow (route to "install unknown apps" settings first
+ * when the permission is missing).
  */
 @HiltViewModel
 class UpdateBannerViewModel @Inject constructor(
@@ -38,7 +40,7 @@ class UpdateBannerViewModel @Inject constructor(
     private val installer: ApkInstaller,
 ) : ViewModel() {
 
-    private val installState = MutableStateFlow(IdleInstall)
+    private val installState = MutableStateFlow(InstallSnapshot(InstallStage.IDLE, null))
 
     val uiState: StateFlow<UpdateBannerUiState> =
         combine(controller.available, installState) { info, install ->
@@ -52,7 +54,7 @@ class UpdateBannerViewModel @Inject constructor(
     fun dismiss(version: String) = controller.dismiss(version)
 
     fun install(info: UpdateInfo) {
-        if (installState.value.stage == InstallStage.DOWNLOADING) return
+        if (installState.value.stage.isBusy()) return
         if (!installer.canInstall()) {
             installer.requestInstallPermission()
             installState.value = InstallSnapshot(
@@ -63,21 +65,28 @@ class UpdateBannerViewModel @Inject constructor(
         }
         viewModelScope.launch {
             installState.value = InstallSnapshot(InstallStage.DOWNLOADING, null)
-            runCatching { installer.downloadApk(info.apkUrl) }
-                .onSuccess { apk ->
-                    installer.launchInstall(apk)
-                    installState.value = IdleInstall
-                }
-                .onFailure { e ->
-                    installState.value = InstallSnapshot(
-                        InstallStage.ERROR,
-                        "Couldn't download update: ${ErrorCopy.fromThrowable(e)}",
-                    )
-                }
+            val apk = download(info.apkUrl)
+            if (apk != null) {
+                // Await the platform's verdict rather than firing an intent and
+                // assuming it worked. On a silent install this suspends until
+                // the process is replaced, so the line below is only reached
+                // when the install did NOT simply succeed.
+                installState.value = InstallSnapshot(InstallStage.INSTALLING, null)
+                val outcome = installer.install(apk)
+                installState.value = InstallSnapshot(outcome.stage(), outcome.message())
+            }
         }
     }
+
+    private suspend fun download(apkUrl: String): File? =
+        runCatching { installer.downloadApk(apkUrl) }
+            .onFailure { e ->
+                installState.value = InstallSnapshot(
+                    InstallStage.ERROR,
+                    "Couldn't download update: ${ErrorCopy.fromThrowable(e)}",
+                )
+            }
+            .getOrNull()
 }
 
 private data class InstallSnapshot(val stage: InstallStage, val message: String?)
-
-private val IdleInstall = InstallSnapshot(InstallStage.IDLE, null)

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

@@ -1,9 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<paths>
-    <!-- The downloaded update APK lives in the app cache dir; the
-         FileProvider exposes just that directory to the system
-         installer via a content:// URI. -->
-    <cache-path
-        name="updates"
-        path="." />
-</paths>