Add multi-photo bulk upload to the Android app

Pick or share several photos at once and post them in one batch, still
against the existing single-image /upload endpoint — no server change.

- Unify the post screen on a list model (PickedItem): a single-photo post
  or share is just a batch of one, so there is one code path.
- Multi-select via PickMultipleVisualMedia and multi-share via
  ACTION_SEND_MULTIPLE (manifest filter added).
- Per-photo caption and EXIF-prefilled date; each card shows its own
  upload status, with a summary and retry-only-failures on re-post.
- Enqueue one WorkManager worker per photo, reusing the durable retry
  queue. UploadQueue now appends a per-item suffix to the slug so a burst
  enqueued in the same second cannot collide and be dropped by
  enqueueUniqueWork.

android/app/src/main/java/ws/inflo/photogallery/MainActivity.kt

@@ -39,8 +39,8 @@ class MainActivity : ComponentActivity() {
                 var showSettings by rememberSaveable { mutableStateOf(!viewModel.isConfigured) }
 
                 val picker = rememberLauncherForActivityResult(
-                    ActivityResultContracts.PickVisualMedia(),
-                ) { uri -> uri?.let(viewModel::selectImage) }
+                    ActivityResultContracts.PickMultipleVisualMedia(),
+                ) { uris -> if (uris.isNotEmpty()) viewModel.selectImages(uris) }
 
                 val notificationPermission = rememberLauncherForActivityResult(
                     ActivityResultContracts.RequestPermission(),
@@ -73,7 +73,7 @@ class MainActivity : ComponentActivity() {
                 } else {
                     PostScreen(
                         state = viewModel.post,
-                        onPickImage = {
+                        onPickImages = {
                             picker.launch(
                                 PickVisualMediaRequest(
                                     ActivityResultContracts.PickVisualMedia.ImageOnly,
@@ -82,6 +82,7 @@ class MainActivity : ComponentActivity() {
                         },
                         onCaptionChange = viewModel::setCaption,
                         onDateChange = viewModel::setDate,
+                        onRemove = viewModel::removeItem,
                         onSubmit = viewModel::submit,
                         onReset = viewModel::clear,
                         onOpenSettings = { showSettings = true },
@@ -98,16 +99,31 @@ class MainActivity : ComponentActivity() {
         consumeShareIntent(intent)
     }
 
-    /** Picks up a photo handed over by the share sheet. */
+    /** Picks up one or several photos handed over by the share sheet. */
     private fun consumeShareIntent(intent: Intent?) {
-        if (intent?.action != Intent.ACTION_SEND) return
-        val uri: Uri? = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
-            intent.getParcelableExtra(Intent.EXTRA_STREAM, Uri::class.java)
-        } else {
-            @Suppress("DEPRECATION")
-            intent.getParcelableExtra(Intent.EXTRA_STREAM)
+        val uris: List<Uri> = when (intent?.action) {
+            Intent.ACTION_SEND -> {
+                val uri: Uri? = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+                    intent.getParcelableExtra(Intent.EXTRA_STREAM, Uri::class.java)
+                } else {
+                    @Suppress("DEPRECATION")
+                    intent.getParcelableExtra(Intent.EXTRA_STREAM)
+                }
+                listOfNotNull(uri)
+            }
+
+            Intent.ACTION_SEND_MULTIPLE -> {
+                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+                    intent.getParcelableArrayListExtra(Intent.EXTRA_STREAM, Uri::class.java)
+                } else {
+                    @Suppress("DEPRECATION")
+                    intent.getParcelableArrayListExtra<Uri>(Intent.EXTRA_STREAM)
+                }.orEmpty()
+            }
+
+            else -> return
         }
-        uri?.let(viewModel::selectImage)
+        if (uris.isNotEmpty()) viewModel.selectImages(uris)
     }
 
     private fun openUrl(url: String) {

android/app/src/main/java/ws/inflo/photogallery/ui/PostScreen.kt

@@ -1,17 +1,20 @@
 package ws.inflo.photogallery.ui
 
+import androidx.compose.foundation.Image
+import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
-import androidx.compose.foundation.layout.aspectRatio
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.rememberScrollState
-import androidx.compose.foundation.verticalScroll
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
 import androidx.compose.material3.Button
 import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.DatePicker
@@ -36,8 +39,6 @@ import androidx.compose.ui.graphics.asImageBitmap
 import androidx.compose.ui.layout.ContentScale
 import androidx.compose.ui.text.font.FontFamily
 import androidx.compose.ui.unit.dp
-import androidx.compose.foundation.Image
-import androidx.compose.foundation.background
 import java.time.Instant
 import java.time.LocalDate
 import java.time.ZoneId
@@ -48,144 +49,214 @@ private val DISPLAY_DATE: DateTimeFormatter = DateTimeFormatter.ofPattern("d MMM
 @Composable
 fun PostScreen(
     state: PostUiState,
-    onPickImage: () -> Unit,
-    onCaptionChange: (String) -> Unit,
-    onDateChange: (LocalDate) -> Unit,
+    onPickImages: () -> Unit,
+    onCaptionChange: (id: String, value: String) -> Unit,
+    onDateChange: (id: String, value: LocalDate) -> Unit,
+    onRemove: (id: String) -> Unit,
     onSubmit: () -> Unit,
     onReset: () -> Unit,
     onOpenSettings: () -> Unit,
     onOpenUrl: (String) -> Unit,
 ) {
-    var datePickerOpen by remember { mutableStateOf(false) }
+    // Which item's date is being edited, if any.
+    var dateEditFor by remember { mutableStateOf<PickedItem?>(null) }
+
+    val pendingCount = state.items.count { it.status !is ItemStatus.Success }
+    val canPost = state.hasItems && !state.posting && pendingCount > 0
 
     Surface(color = MaterialTheme.colorScheme.background, modifier = Modifier.fillMaxSize()) {
-        Column(
+        LazyColumn(
             modifier = Modifier
                 .fillMaxSize()
-                .verticalScroll(rememberScrollState())
                 .padding(20.dp),
         ) {
-            Row(
-                modifier = Modifier.fillMaxWidth(),
-                horizontalArrangement = Arrangement.SpaceBetween,
-                verticalAlignment = Alignment.CenterVertically,
-            ) {
-                Text("Post a photo", style = MaterialTheme.typography.headlineSmall, color = GruvGreen)
-                TextButton(onClick = onOpenSettings) { Text("Settings") }
+            item {
+                Row(
+                    modifier = Modifier.fillMaxWidth(),
+                    horizontalArrangement = Arrangement.SpaceBetween,
+                    verticalAlignment = Alignment.CenterVertically,
+                ) {
+                    Text("Post photos", style = MaterialTheme.typography.headlineSmall, color = GruvGreen)
+                    TextButton(onClick = onOpenSettings) { Text("Settings") }
+                }
+                Spacer(Modifier.height(12.dp))
             }
 
-            Spacer(Modifier.height(12.dp))
+            item {
+                OutlinedButton(onClick = onPickImages, modifier = Modifier.fillMaxWidth()) {
+                    Text(if (state.hasItems) "Choose different photos" else "Choose photos")
+                }
+                Spacer(Modifier.height(16.dp))
+            }
 
-            Box(
-                modifier = Modifier
-                    .fillMaxWidth()
-                    .aspectRatio(1f)
-                    .background(GruvBg1),
-                contentAlignment = Alignment.Center,
-            ) {
-                val preview = state.preview
-                when {
-                    preview != null -> Image(
-                        bitmap = preview.asImageBitmap(),
-                        contentDescription = null,
-                        contentScale = ContentScale.Fit,
-                        modifier = Modifier.fillMaxSize(),
-                    )
-                    state.imageUri != null -> CircularProgressIndicator(color = GruvAqua)
-                    else -> Text("No photo selected", color = GruvFg4)
+            if (!state.hasItems) {
+                item {
+                    Box(
+                        modifier = Modifier
+                            .fillMaxWidth()
+                            .height(160.dp)
+                            .background(GruvBg1),
+                        contentAlignment = Alignment.Center,
+                    ) {
+                        Text("No photos selected", color = GruvFg4)
+                    }
                 }
             }
 
-            Spacer(Modifier.height(12.dp))
-
-            OutlinedButton(onClick = onPickImage, modifier = Modifier.fillMaxWidth()) {
-                Text(if (state.imageUri == null) "Choose photo" else "Choose a different photo")
+            items(state.items, key = { it.id }) { item ->
+                ItemCard(
+                    item = item,
+                    onCaptionChange = { onCaptionChange(item.id, it) },
+                    onEditDate = { dateEditFor = item },
+                    onRemove = { onRemove(item.id) },
+                    onOpenUrl = onOpenUrl,
+                )
+                Spacer(Modifier.height(12.dp))
             }
 
-            Spacer(Modifier.height(16.dp))
-
-            OutlinedTextField(
-                value = state.caption,
-                onValueChange = onCaptionChange,
-                label = { Text("Caption") },
-                placeholder = { Text("Defaults to the filename if left blank") },
-                modifier = Modifier.fillMaxWidth(),
-            )
-
-            Spacer(Modifier.height(12.dp))
-
-            OutlinedButton(
-                onClick = { datePickerOpen = true },
-                modifier = Modifier.fillMaxWidth(),
-            ) {
-                Text("Date:  ${state.date.format(DISPLAY_DATE)}")
-            }
-
-            Spacer(Modifier.height(20.dp))
-
-            Button(
-                onClick = onSubmit,
-                enabled = state.imageUri != null && state.status !is PostStatus.Uploading,
-                modifier = Modifier.fillMaxWidth(),
-            ) {
-                Text(if (state.status is PostStatus.Uploading) "Posting…" else "Post")
-            }
-
-            Spacer(Modifier.height(16.dp))
-
-            when (val status = state.status) {
-                is PostStatus.Error -> Text(status.message, color = GruvRed)
-
-                is PostStatus.Success -> Column {
-                    Text("Posted.", color = GruvAqua)
-                    status.note?.let {
-                        Spacer(Modifier.height(4.dp))
-                        Text("Note: $it", color = GruvFg4, style = MaterialTheme.typography.bodySmall)
-                    }
+            if (state.hasItems) {
+                item {
                     Spacer(Modifier.height(8.dp))
-                    Row {
-                        TextButton(onClick = { onOpenUrl(status.url) }) { Text("Open") }
-                        TextButton(onClick = onReset) { Text("Post another") }
+                    Button(
+                        onClick = onSubmit,
+                        enabled = canPost,
+                        modifier = Modifier.fillMaxWidth(),
+                    ) {
+                        Text(
+                            when {
+                                state.posting -> "Posting… (${state.succeeded}/${state.items.size})"
+                                pendingCount == 0 -> "All posted"
+                                pendingCount == 1 -> "Post 1 photo"
+                                else -> "Post $pendingCount photos"
+                            },
+                        )
+                    }
+
+                    if (state.allDone) {
+                        Spacer(Modifier.height(12.dp))
+                        val summary = buildString {
+                            append("${state.succeeded} posted")
+                            if (state.failed > 0) append(", ${state.failed} failed")
+                        }
+                        Text(summary, color = if (state.failed > 0) GruvRed else GruvAqua)
+                        Spacer(Modifier.height(8.dp))
+                        TextButton(onClick = onReset) { Text("Clear") }
                     }
                 }
-
-                else -> Unit
             }
 
             state.lastPost?.let { last ->
-                Spacer(Modifier.height(24.dp))
-                HorizontalDivider(color = GruvBg2)
-                Spacer(Modifier.height(12.dp))
-                Text("Last post", color = GruvFg4, style = MaterialTheme.typography.labelMedium)
-                Spacer(Modifier.height(4.dp))
-                Text(
-                    last.caption.ifBlank { last.slug },
-                    color = GruvFg,
-                    style = MaterialTheme.typography.bodyMedium,
-                )
-                Text(
-                    last.slug,
-                    color = GruvFg4,
-                    fontFamily = FontFamily.Monospace,
-                    style = MaterialTheme.typography.bodySmall,
-                )
-                TextButton(onClick = { onOpenUrl(last.url) }) { Text("Open") }
+                item {
+                    Spacer(Modifier.height(24.dp))
+                    HorizontalDivider(color = GruvBg2)
+                    Spacer(Modifier.height(12.dp))
+                    Text("Last post", color = GruvFg4, style = MaterialTheme.typography.labelMedium)
+                    Spacer(Modifier.height(4.dp))
+                    Text(
+                        last.caption.ifBlank { last.slug },
+                        color = GruvFg,
+                        style = MaterialTheme.typography.bodyMedium,
+                    )
+                    Text(
+                        last.slug,
+                        color = GruvFg4,
+                        fontFamily = FontFamily.Monospace,
+                        style = MaterialTheme.typography.bodySmall,
+                    )
+                    TextButton(onClick = { onOpenUrl(last.url) }) { Text("Open") }
+                }
             }
         }
     }
 
-    if (datePickerOpen) {
+    dateEditFor?.let { editing ->
         DatePickerModal(
-            initial = state.date,
-            onDismiss = { datePickerOpen = false },
+            initial = editing.date,
+            onDismiss = { dateEditFor = null },
             onConfirm = {
-                onDateChange(it)
-                datePickerOpen = false
+                onDateChange(editing.id, it)
+                dateEditFor = null
             },
         )
     }
 }
 
+@Composable
+private fun ItemCard(
+    item: PickedItem,
+    onCaptionChange: (String) -> Unit,
+    onEditDate: () -> Unit,
+    onRemove: () -> Unit,
+    onOpenUrl: (String) -> Unit,
+) {
+    Row(modifier = Modifier.fillMaxWidth()) {
+        Box(
+            modifier = Modifier
+                .size(84.dp)
+                .background(GruvBg1),
+            contentAlignment = Alignment.Center,
+        ) {
+            val preview = item.preview
+            when {
+                preview != null -> Image(
+                    bitmap = preview.asImageBitmap(),
+                    contentDescription = null,
+                    contentScale = ContentScale.Crop,
+                    modifier = Modifier.fillMaxSize(),
+                )
+                else -> CircularProgressIndicator(color = GruvAqua, modifier = Modifier.size(24.dp))
+            }
+        }
+
+        Spacer(Modifier.width(12.dp))
+
+        Column(modifier = Modifier.weight(1f)) {
+            OutlinedTextField(
+                value = item.caption,
+                onValueChange = onCaptionChange,
+                label = { Text("Caption") },
+                singleLine = true,
+                enabled = item.status !is ItemStatus.Uploading,
+                modifier = Modifier.fillMaxWidth(),
+            )
+            Spacer(Modifier.height(6.dp))
+            Row(verticalAlignment = Alignment.CenterVertically) {
+                OutlinedButton(
+                    onClick = onEditDate,
+                    enabled = item.status !is ItemStatus.Uploading,
+                ) {
+                    Text(item.date.format(DISPLAY_DATE))
+                }
+                Spacer(Modifier.width(8.dp))
+                ItemStatusLabel(item.status, onOpenUrl)
+            }
+        }
+
+        Spacer(Modifier.width(8.dp))
+
+        when (item.status) {
+            is ItemStatus.Uploading ->
+                CircularProgressIndicator(color = GruvAqua, modifier = Modifier.size(20.dp))
+            is ItemStatus.Success -> Unit
+            else -> TextButton(onClick = onRemove) { Text("✕", color = GruvFg4) }
+        }
+    }
+}
+
+@Composable
+private fun ItemStatusLabel(status: ItemStatus, onOpenUrl: (String) -> Unit) {
+    when (status) {
+        is ItemStatus.Pending -> Unit
+        is ItemStatus.Uploading -> Text("Uploading…", color = GruvFg4, style = MaterialTheme.typography.bodySmall)
+        is ItemStatus.Success -> TextButton(onClick = { onOpenUrl(status.url) }) { Text("View") }
+        is ItemStatus.Error -> Text(
+            status.message,
+            color = GruvRed,
+            style = MaterialTheme.typography.bodySmall,
+        )
+    }
+}
+
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
 private fun DatePickerModal(

android/app/src/main/java/ws/inflo/photogallery/ui/UploadViewModel.kt

@@ -24,22 +24,41 @@ import java.io.File
 import java.time.LocalDate
 import java.util.UUID
 
-sealed interface PostStatus {
-    data object Idle : PostStatus
-    data object Uploading : PostStatus
-    data class Success(val url: String, val note: String?) : PostStatus
-    data class Error(val message: String) : PostStatus
+/** Per-photo status within a batch. */
+sealed interface ItemStatus {
+    data object Pending : ItemStatus
+    data object Uploading : ItemStatus
+    data class Success(val url: String, val note: String?) : ItemStatus
+    data class Error(val message: String) : ItemStatus
 }
 
-data class PostUiState(
-    val imageUri: Uri? = null,
+/**
+ * One photo in the batch. A single-photo post (picker or share) is just a
+ * batch of one, so the whole screen runs a single code path.
+ */
+data class PickedItem(
+    val id: String = UUID.randomUUID().toString(),
+    val source: Uri,
     val preview: Bitmap? = null,
     val caption: String = "",
     val date: LocalDate = LocalDate.now(),
-    val status: PostStatus = PostStatus.Idle,
-    val lastPost: LastPost? = null,
+    val status: ItemStatus = ItemStatus.Pending,
 )
 
+data class PostUiState(
+    val items: List<PickedItem> = emptyList(),
+    val lastPost: LastPost? = null,
+) {
+    val posting: Boolean get() = items.any { it.status is ItemStatus.Uploading }
+    val hasItems: Boolean get() = items.isNotEmpty()
+    val succeeded: Int get() = items.count { it.status is ItemStatus.Success }
+    val failed: Int get() = items.count { it.status is ItemStatus.Error }
+    /** True once every item has reached a terminal state and at least one ran. */
+    val allDone: Boolean
+        get() = items.isNotEmpty() &&
+            items.all { it.status is ItemStatus.Success || it.status is ItemStatus.Error }
+}
+
 data class SettingsUiState(
     val baseUrl: String = "",
     val username: String = "",
@@ -69,57 +88,81 @@ class UploadViewModel(app: Application) : AndroidViewModel(app) {
 
     // ── Post screen ─────────────────────────────────────────────────────────
 
-    fun selectImage(uri: Uri) {
-        post = post.copy(imageUri = uri, status = PostStatus.Idle, preview = null)
-        viewModelScope.launch {
-            val context = getApplication<Application>()
-            val preview = withContext(Dispatchers.IO) { ImagePrep.preview(context, uri) }
-            val captured = withContext(Dispatchers.IO) { ImagePrep.captureDate(context, uri) }
-            post = post.copy(preview = preview, date = captured ?: LocalDate.now())
+    /** Replaces the current selection with [uris] and loads each preview. */
+    fun selectImages(uris: List<Uri>) {
+        if (uris.isEmpty()) return
+        val items = uris.map { PickedItem(source = it) }
+        post = post.copy(items = items)
+
+        val context = getApplication<Application>()
+        for (item in items) {
+            viewModelScope.launch {
+                val preview = withContext(Dispatchers.IO) {
+                    ImagePrep.preview(context, item.source, maxDimension = 256)
+                }
+                val captured = withContext(Dispatchers.IO) {
+                    ImagePrep.captureDate(context, item.source)
+                }
+                updateItem(item.id) {
+                    it.copy(preview = preview, date = captured ?: it.date)
+                }
+            }
         }
     }
 
-    fun setCaption(value: String) {
-        post = post.copy(caption = value)
+    fun setCaption(id: String, value: String) {
+        updateItem(id) { it.copy(caption = value) }
     }
 
-    fun setDate(value: LocalDate) {
-        post = post.copy(date = value)
+    fun setDate(id: String, value: LocalDate) {
+        updateItem(id) { it.copy(date = value) }
+    }
+
+    fun removeItem(id: String) {
+        // A photo already uploading keeps its worker; just drop it from the UI.
+        post = post.copy(items = post.items.filterNot { it.id == id })
     }
 
     fun clear() {
         post = PostUiState(lastPost = settings.lastPost)
     }
 
+    /** Uploads every item not already posted. Re-running retries only failures. */
     fun submit() {
-        val uri = post.imageUri ?: return
         if (!settings.isConfigured) {
-            post = post.copy(status = PostStatus.Error("Set the server URL and credentials first"))
+            post = post.copy(
+                items = post.items.map {
+                    if (it.status is ItemStatus.Success) it
+                    else it.copy(status = ItemStatus.Error("Set the server URL and credentials first"))
+                },
+            )
             return
         }
 
-        post = post.copy(status = PostStatus.Uploading)
+        val pending = post.items.filter { it.status !is ItemStatus.Success }
+        if (pending.isEmpty()) return
 
-        viewModelScope.launch {
-            val context = getApplication<Application>()
-
-            // Stage the bytes into our own cache before handing the job to
-            // WorkManager. A content:// URI from the share sheet is only
-            // readable while the grant lasts, and a retry can fire long after
-            // the activity that received it is gone.
-            val staged = withContext(Dispatchers.IO) { stage(uri) }
-            if (staged == null) {
-                post = post.copy(status = PostStatus.Error("Could not read the selected image"))
-                return@launch
+        val context = getApplication<Application>()
+        for (item in pending) {
+            updateItem(item.id) { it.copy(status = ItemStatus.Uploading) }
+            viewModelScope.launch {
+                val staged = withContext(Dispatchers.IO) { stage(item.source) }
+                if (staged == null) {
+                    updateItem(item.id) {
+                        it.copy(status = ItemStatus.Error("Could not read the selected image"))
+                    }
+                    return@launch
+                }
+                val current = post.items.firstOrNull { it.id == item.id } ?: return@launch
+                val workId = UploadQueue.enqueue(
+                    context = context,
+                    uri = Uri.fromFile(staged),
+                    caption = current.caption,
+                    date = current.date,
+                    uniqueSuffix = item.id.take(6),
+                )
+                observe(item.id, workId)
             }
-
-            val id = UploadQueue.enqueue(
-                context = context,
-                uri = Uri.fromFile(staged),
-                caption = post.caption,
-                date = post.date,
-            )
-            observe(id)
         }
     }
 
@@ -136,32 +179,35 @@ class UploadViewModel(app: Application) : AndroidViewModel(app) {
         }
     }
 
-    private fun observe(id: UUID) {
+    private fun observe(itemId: String, workId: UUID) {
         viewModelScope.launch {
-            WorkManager.getInstance(getApplication()).getWorkInfoByIdFlow(id).collect { info ->
+            WorkManager.getInstance(getApplication()).getWorkInfoByIdFlow(workId).collect { info ->
                 if (info == null) return@collect
                 when (info.state) {
                     WorkInfo.State.SUCCEEDED -> {
-                        post = post.copy(
-                            status = PostStatus.Success(
-                                url = info.outputData.getString(UploadWorker.KEY_RESULT_URL).orEmpty(),
-                                note = info.outputData.getString(UploadWorker.KEY_RESULT_NOTE),
-                            ),
-                            lastPost = settings.lastPost,
-                        )
+                        updateItem(itemId) {
+                            it.copy(
+                                status = ItemStatus.Success(
+                                    url = info.outputData.getString(UploadWorker.KEY_RESULT_URL).orEmpty(),
+                                    note = info.outputData.getString(UploadWorker.KEY_RESULT_NOTE),
+                                ),
+                            )
+                        }
+                        post = post.copy(lastPost = settings.lastPost)
                     }
 
-                    WorkInfo.State.FAILED -> {
-                        post = post.copy(
-                            status = PostStatus.Error(
+                    WorkInfo.State.FAILED -> updateItem(itemId) {
+                        it.copy(
+                            status = ItemStatus.Error(
                                 info.outputData.getString(UploadWorker.KEY_RESULT_ERROR)
                                     ?: "Upload failed",
                             ),
                         )
                     }
 
-                    WorkInfo.State.CANCELLED ->
-                        post = post.copy(status = PostStatus.Error("Upload cancelled"))
+                    WorkInfo.State.CANCELLED -> updateItem(itemId) {
+                        it.copy(status = ItemStatus.Error("Upload cancelled"))
+                    }
 
                     else -> Unit
                 }
@@ -169,6 +215,10 @@ class UploadViewModel(app: Application) : AndroidViewModel(app) {
         }
     }
 
+    private inline fun updateItem(id: String, transform: (PickedItem) -> PickedItem) {
+        post = post.copy(items = post.items.map { if (it.id == id) transform(it) else it })
+    }
+
     // ── Settings screen ─────────────────────────────────────────────────────
 
     fun setBaseUrl(value: String) {

android/app/src/main/java/ws/inflo/photogallery/work/UploadQueue.kt

@@ -18,9 +18,11 @@ object UploadQueue {
 
     /**
      * Slug format. Uses the enqueue wall-clock time rather than the photo's
-     * capture time: a burst of frames shot in the same second would collide on
-     * capture time, whereas posts are made one at a time. The real capture date
-     * still travels in the `date` field and lands in the .toml sidecar.
+     * capture time: capture time collides across a burst. A [uniqueSuffix] is
+     * appended so that a bulk post — several photos enqueued in the same second
+     * — cannot collide either; without it enqueueUniqueWork would silently drop
+     * the duplicates. The real capture date still travels in the `date` field
+     * and lands in the .toml sidecar.
      */
     private val SLUG_FORMAT: DateTimeFormatter =
         DateTimeFormatter.ofPattern("yyyy-MM-dd-HHmmss")
@@ -32,8 +34,9 @@ object UploadQueue {
         uri: Uri,
         caption: String,
         date: LocalDate,
+        uniqueSuffix: String,
     ): UUID {
-        val slug = LocalDateTime.now().format(SLUG_FORMAT)
+        val slug = LocalDateTime.now().format(SLUG_FORMAT) + "-" + uniqueSuffix
 
         val request = OneTimeWorkRequestBuilder<UploadWorker>()
             .setInputData(