refactor(uploads): drop legacy multipart helpers; route Android UI through presigned flow

The KMP shared layer's task-completion-with-images path now exclusively
uses the presigned-URL flow: each image is compressed, uploaded directly
to B2 via APILayer.uploadImage, and the resulting upload_ids are passed
to /api/task-completions/ as JSON. Bytes never traverse our API server.

Changes:
  - TaskCompletionViewModel.createTaskCompletionWithImages now does the
    presign→POST→collect-ids dance internally. The signature stays the
    same so the three Android UI call sites (TasksScreen, AllTasksScreen,
    ResidenceDetailScreen, CompleteTaskDialog, CompleteTaskScreen) need
    no changes.
  - APILayer.createTaskCompletionWithImages removed (dead).
  - TaskCompletionApi.createCompletionWithImages removed (the multipart
    HTTP helper that posted to the legacy POST /api/task-completions/
    multipart endpoint).
  - TaskCompletionCreateRequest.imageUrls field removed.
  - Three Swift call sites (CompleteTaskView, WidgetActionProcessor,
    PushNotificationManager) updated to drop the imageUrls argument.
  - Two Kotlin call sites (CompleteTaskDialog, CompleteTaskScreen) updated.

Image uploads now match WhatsApp/Slack-class architecture: client-side
compression + direct-to-storage upload + lightweight JSON entity create.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

composeApp/src/commonMain/kotlin/com/tt/honeyDue/models/TaskCompletion.kt

@@ -13,8 +13,7 @@ data class TaskCompletionCreateRequest(
     val notes: String? = null,
     @SerialName("actual_cost") val actualCost: Double? = null,
     val rating: Int? = null,  // 1-5 star rating
-    @SerialName("image_urls") val imageUrls: List<String>? = null,  // Legacy: URLs returned by /api/uploads/* multipart endpoints
-    @SerialName("upload_ids") val uploadIds: List<Int>? = null      // New: pending_uploads.id values from /api/uploads/presign + direct B2 POST
+    @SerialName("upload_ids") val uploadIds: List<Int>? = null      // pending_uploads.id values from /api/uploads/presign + direct B2 POST
 )
 
 /**

composeApp/src/commonMain/kotlin/com/tt/honeyDue/network/APILayer.kt

@@ -816,30 +816,6 @@ object APILayer {
         }
     }
 
-    suspend fun createTaskCompletionWithImages(
-        request: TaskCompletionCreateRequest,
-        images: List<ByteArray>,
-        imageFileNames: List<String>
-    ): ApiResult<TaskCompletionResponse> {
-        val token = getToken() ?: return ApiResult.Error("Not authenticated", 401)
-        val result = taskCompletionApi.createCompletionWithImages(token, request, images, imageFileNames)
-
-        if (result is ApiResult.Success) {
-            // Update summary from response - eliminates need for separate getSummary call
-            DataManager.setTotalSummary(result.data.summary)
-            // The response includes the updated task, update it in DataManager
-            result.data.data.updatedTask?.let { updatedTask ->
-                DataManager.updateTask(updatedTask)
-            }
-            return ApiResult.Success(result.data.data)
-        }
-
-        return when (result) {
-            is ApiResult.Error -> result
-            else -> ApiResult.Error("Unknown error")
-        }
-    }
-
     /**
      * Get all completions for a specific task
      */

composeApp/src/commonMain/kotlin/com/tt/honeyDue/network/TaskCompletionApi.kt

@@ -94,47 +94,4 @@ class TaskCompletionApi(private val client: HttpClient = ApiClient.httpClient) {
         }
     }
 
-    suspend fun createCompletionWithImages(
-        token: String,
-        request: TaskCompletionCreateRequest,
-        images: List<ByteArray> = emptyList(),
-        imageFileNames: List<String> = emptyList()
-    ): ApiResult<WithSummaryResponse<TaskCompletionResponse>> {
-        return try {
-            val response = client.submitFormWithBinaryData(
-                url = "$baseUrl/task-completions/",
-                formData = formData {
-                    // Add text fields
-                    append("task_id", request.taskId.toString())
-                    request.completedAt?.let { append("completed_at", it) }
-                    request.actualCost?.let { append("actual_cost", it.toString()) }
-                    request.notes?.let { append("notes", it) }
-                    request.rating?.let { append("rating", it.toString()) }
-
-                    // Add image files
-                    images.forEachIndexed { index, imageBytes ->
-                        val fileName = imageFileNames.getOrNull(index) ?: "image_$index.jpg"
-                        append(
-                            "images",
-                            imageBytes,
-                            Headers.build {
-                                append(HttpHeaders.ContentType, "image/jpeg")
-                                append(HttpHeaders.ContentDisposition, "filename=\"$fileName\"")
-                            }
-                        )
-                    }
-                }
-            ) {
-                header("Authorization", "Token $token")
-            }
-
-            if (response.status.isSuccess()) {
-                ApiResult.Success(response.body())
-            } else {
-                ApiResult.Error("Failed to create completion with images", response.status.value)
-            }
-        } catch (e: Exception) {
-            ApiResult.Error(e.message ?: "Unknown error occurred")
-        }
-    }
 }

composeApp/src/commonMain/kotlin/com/tt/honeyDue/ui/components/CompleteTaskDialog.kt

@@ -377,7 +377,8 @@ fun CompleteTaskDialog(
                             actualCost = actualCost.ifBlank { null }?.toDoubleOrNull(),
                             notes = notesWithContractor,
                             rating = rating,
-                            imageUrls = null  // Images uploaded separately and URLs added by handler
+                            // upload_ids populated by the ViewModel after each
+                            // image is uploaded directly to B2.
                         ),
                         selectedImages
                     )

composeApp/src/commonMain/kotlin/com/tt/honeyDue/ui/screens/CompleteTaskScreen.kt

@@ -421,7 +421,8 @@ fun CompleteTaskScreen(
                                 actualCost = actualCost.ifBlank { null }?.toDoubleOrNull(),
                                 notes = notesWithContractor,
                                 rating = rating,
-                                imageUrls = null
+                                // upload_ids populated by the ViewModel after each
+                                // image is uploaded directly to B2.
                             ),
                             selectedImages
                         )

composeApp/src/commonMain/kotlin/com/tt/honeyDue/viewmodel/TaskCompletionViewModel.kt

@@ -25,38 +25,61 @@ class TaskCompletionViewModel : ViewModel() {
     }
 
     /**
-     * Create task completion with images.
+     * Create task completion with images, using the presigned-URL upload flow.
+     *
+     * For each image: compress, presign + POST direct to B2, collect the
+     * upload_id. Once all uploads succeed, create the completion with the
+     * collected upload_ids in a single JSON request. Bytes never traverse
+     * our API server.
+     *
+     * If any individual upload fails, the whole batch fails — partial
+     * pending_uploads rows are reaped server-side by the hourly cleanup
+     * cron, so there's nothing to clean up client-side.
      *
      * @param request The completion request data
      * @param images List of ImageData (from platform-specific image pickers)
      */
     fun createTaskCompletionWithImages(
         request: TaskCompletionCreateRequest,
-        images: List<com.tt.honeyDue.platform.ImageData> = emptyList()
+        images: List<com.tt.honeyDue.platform.ImageData> = emptyList(),
     ) {
         viewModelScope.launch {
             _createCompletionState.value = ApiResult.Loading
 
-            // Compress images and prepare for upload
-            val compressedImages = images.map { ImageCompressor.compressImage(it) }
-            val imageFileNames = images.mapIndexed { index, image ->
-                // Always use .jpg extension since we compress to JPEG
-                val baseName = image.fileName.ifBlank { "completion_$index" }
-                if (baseName.endsWith(".jpg", ignoreCase = true) ||
-                    baseName.endsWith(".jpeg", ignoreCase = true)) {
-                    baseName
-                } else {
-                    // Remove any existing extension and add .jpg
-                    baseName.substringBeforeLast('.', baseName) + ".jpg"
+            val uploadIds = mutableListOf<Int>()
+            for ((index, image) in images.withIndex()) {
+                val compressed = ImageCompressor.compressImage(image)
+                val fileName = run {
+                    val base = image.fileName.ifBlank { "completion_$index" }
+                    if (base.endsWith(".jpg", ignoreCase = true) ||
+                        base.endsWith(".jpeg", ignoreCase = true)
+                    ) base else base.substringBeforeLast('.', base) + ".jpg"
+                }
+                val uploadResult = APILayer.uploadImage(
+                    category = "completion",
+                    contentType = "image/jpeg",
+                    bytes = compressed,
+                    fileName = fileName,
+                )
+                when (uploadResult) {
+                    is ApiResult.Success -> uploadIds += uploadResult.data
+                    is ApiResult.Error -> {
+                        _createCompletionState.value = ApiResult.Error(uploadResult.message, uploadResult.code)
+                        return@launch
+                    }
+                    else -> {
+                        _createCompletionState.value = ApiResult.Error("Upload failed in unexpected state")
+                        return@launch
+                    }
                 }
             }
 
-            // Use APILayer which handles DataManager updates and summary refresh
-            _createCompletionState.value = APILayer.createTaskCompletionWithImages(
-                request = request,
-                images = compressedImages,
-                imageFileNames = imageFileNames
-            )
+            val withUploads = if (uploadIds.isNotEmpty()) {
+                request.copy(uploadIds = uploadIds.toList())
+            } else {
+                request
+            }
+            _createCompletionState.value = APILayer.createTaskCompletion(withUploads)
         }
     }