06/19 Update inspections/issues sent via email, and duplicated issue photos issues

JanitorialQC/Views/Dashboard/FormFieldView.swift

@@ -606,20 +606,36 @@ struct MultiLibraryPickerView: UIViewControllerRepresentable {
             picker.dismiss(animated: true)
             guard !results.isEmpty else { return }
 
-            var images: [UIImage] = []
+            // PHItemProvider.loadObject's completion handler can be invoked on
+            // arbitrary background queues, potentially concurrently for
+            // different results. Appending to a shared `[UIImage]` from
+            // multiple threads without synchronization is a data race —
+            // Swift's Array is not thread-safe, and concurrent mutation can
+            // corrupt its storage, manifesting as duplicated, dropped, or
+            // reordered photos in the final result. This was the root cause
+            // of duplicated Photo Library attachments on issues.
+            //
+            // Fix: pre-size the array to one slot per result and write each
+            // loaded image into its own fixed index, guarded by a single
+            // serial queue so writes never overlap. Each slot is written at
+            // most once, so duplication is structurally impossible.
+            var images = [UIImage?](repeating: nil, count: results.count)
+            let writeQueue = DispatchQueue(label: "jqc.photopicker.write")
             let group = DispatchGroup()
 
-            for result in results {
+            for (index, result) in results.enumerated() {
                 guard result.itemProvider.canLoadObject(ofClass: UIImage.self) else { continue }
                 group.enter()
                 result.itemProvider.loadObject(ofClass: UIImage.self) { object, _ in
-                    if let img = object as? UIImage { images.append(img) }
+                    if let img = object as? UIImage {
+                        writeQueue.sync { images[index] = img }
+                    }
                     group.leave()
                 }
             }
 
             group.notify(queue: .main) {
-                self.parent.onSelected(images)
+                self.parent.onSelected(images.compactMap { $0 })
             }
         }
     }