Add a tags field to the Android and desktop uploaders

Each photo card gains a free-text tags input, sent as a raw
comma-separated `tags` form field on upload. The server normalizes it
(parseTags), so the clients stay dumb — no tag parsing on-device.

- Android: PickedItem.tags + setTags; threaded through UploadQueue →
  UploadWorker → UploadClient's multipart.
- Desktop: a tags QLineEdit per PhotoItemWidget; UploadClient.upload sends
  it.

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

@@ -81,6 +81,7 @@ class MainActivity : ComponentActivity() {
                             )
                         },
                         onCaptionChange = viewModel::setCaption,
+                        onTagsChange = viewModel::setTags,
                         onDateChange = viewModel::setDate,
                         onRemove = viewModel::removeItem,
                         onSubmit = viewModel::submit,

android/app/src/main/java/ws/inflo/photogallery/net/UploadClient.kt

@@ -60,6 +60,7 @@ class UploadClient(
         fileName: String,
         caption: String,
         date: String,
+        tags: String,
     ): UploadOutcome {
         val mediaType = if (fileName.endsWith(".png", ignoreCase = true)) {
             "image/png".toMediaType()
@@ -72,6 +73,7 @@ class UploadClient(
             .addFormDataPart("image", fileName, file.asRequestBody(mediaType))
             .addFormDataPart("caption", caption)
             .addFormDataPart("date", date)
+            .addFormDataPart("tags", tags)
             .build()
 
         val request = Request.Builder()

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

@@ -51,6 +51,7 @@ fun PostScreen(
     state: PostUiState,
     onPickImages: () -> Unit,
     onCaptionChange: (id: String, value: String) -> Unit,
+    onTagsChange: (id: String, value: String) -> Unit,
     onDateChange: (id: String, value: LocalDate) -> Unit,
     onRemove: (id: String) -> Unit,
     onSubmit: () -> Unit,
@@ -107,6 +108,7 @@ fun PostScreen(
                 ItemCard(
                     item = item,
                     onCaptionChange = { onCaptionChange(item.id, it) },
+                    onTagsChange = { onTagsChange(item.id, it) },
                     onEditDate = { dateEditFor = item },
                     onRemove = { onRemove(item.id) },
                     onOpenUrl = onOpenUrl,
@@ -185,6 +187,7 @@ fun PostScreen(
 private fun ItemCard(
     item: PickedItem,
     onCaptionChange: (String) -> Unit,
+    onTagsChange: (String) -> Unit,
     onEditDate: () -> Unit,
     onRemove: () -> Unit,
     onOpenUrl: (String) -> Unit,
@@ -220,6 +223,16 @@ private fun ItemCard(
                 modifier = Modifier.fillMaxWidth(),
             )
             Spacer(Modifier.height(6.dp))
+            OutlinedTextField(
+                value = item.tags,
+                onValueChange = onTagsChange,
+                label = { Text("Tags") },
+                placeholder = { Text("comma-separated") },
+                singleLine = true,
+                enabled = item.status !is ItemStatus.Uploading,
+                modifier = Modifier.fillMaxWidth(),
+            )
+            Spacer(Modifier.height(6.dp))
             Row(verticalAlignment = Alignment.CenterVertically) {
                 OutlinedButton(
                     onClick = onEditDate,

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

@@ -41,6 +41,7 @@ data class PickedItem(
     val source: Uri,
     val preview: Bitmap? = null,
     val caption: String = "",
+    val tags: String = "", // raw comma-separated; the server normalizes
     val date: LocalDate = LocalDate.now(),
     val status: ItemStatus = ItemStatus.Pending,
 )
@@ -114,6 +115,10 @@ class UploadViewModel(app: Application) : AndroidViewModel(app) {
         updateItem(id) { it.copy(caption = value) }
     }
 
+    fun setTags(id: String, value: String) {
+        updateItem(id) { it.copy(tags = value) }
+    }
+
     fun setDate(id: String, value: LocalDate) {
         updateItem(id) { it.copy(date = value) }
     }
@@ -159,6 +164,7 @@ class UploadViewModel(app: Application) : AndroidViewModel(app) {
                     uri = Uri.fromFile(staged),
                     caption = current.caption,
                     date = current.date,
+                    tags = current.tags,
                     uniqueSuffix = item.id.take(6),
                 )
                 observe(item.id, workId)

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

@@ -34,6 +34,7 @@ object UploadQueue {
         uri: Uri,
         caption: String,
         date: LocalDate,
+        tags: String,
         uniqueSuffix: String,
     ): UUID {
         val slug = LocalDateTime.now().format(SLUG_FORMAT) + "-" + uniqueSuffix
@@ -45,6 +46,7 @@ object UploadQueue {
                     .putString(UploadWorker.KEY_SLUG, slug)
                     .putString(UploadWorker.KEY_CAPTION, caption)
                     .putString(UploadWorker.KEY_DATE, date.format(ISO_DATE))
+                    .putString(UploadWorker.KEY_TAGS, tags)
                     .build(),
             )
             .setConstraints(

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

@@ -38,6 +38,7 @@ class UploadWorker(
         val slug = inputData.getString(KEY_SLUG) ?: return@withContext Result.failure()
         val caption = inputData.getString(KEY_CAPTION).orEmpty()
         val date = inputData.getString(KEY_DATE).orEmpty()
+        val tags = inputData.getString(KEY_TAGS).orEmpty()
 
         val settings = SettingsStore(applicationContext)
         if (!settings.isConfigured) {
@@ -66,6 +67,7 @@ class UploadWorker(
             fileName = prepared.file.name,
             caption = caption,
             date = date,
+            tags = tags,
         )
 
         // Keep the staged and prepared copies only while a retry might still
@@ -147,6 +149,7 @@ class UploadWorker(
         const val KEY_SLUG = "slug"
         const val KEY_CAPTION = "caption"
         const val KEY_DATE = "date"
+        const val KEY_TAGS = "tags"
 
         const val KEY_RESULT_SLUG = "result_slug"
         const val KEY_RESULT_URL = "result_url"