#5 fix camera capture preview after shooting

- Dismiss the camera fullScreenCover through the SwiftUI binding
  synchronously in the picker delegate before background file
  preparation, so UIImagePickerController no longer dismisses itself
  and desynchronizes the presentation state that the preview sheet
  waits on.
- Keep the archive-sync suspension reserved across the dismissal and
  surface an explicit error when the captured file fails to prepare.
- Add verify.sh invariants for the camera dismissal flow.

Sources/Shared/UI/ChatView.swift

@@ -254,13 +254,23 @@ struct ChatView: View {
                 }
             ) {
                 SystemPhotoCameraView(
-                    onMedia: { result in
+                    onDismissRequest: {
+                        // Runs synchronously in the picker delegate while the
+                        // camera is still presented: dismiss through the
+                        // binding so SwiftUI owns the transition, and reserve
+                        // the archive-sync suspension across the dismissal
+                        // while the file is prepared in the background.
                         showingPhotoCamera = false
+                        photoCameraIsPreparingResult = true
+                    },
+                    onMedia: { result in
                         switch result {
                         case .success(let media):
                             photoCameraIsPreparingResult = true
                             Task { await stageCapturedMedia(media) }
                         case .failure(let error):
+                            photoCameraIsPreparingResult = false
+                            releaseArchiveSyncAfterCapture()
                             model.errorMessage = error.localizedDescription
                         }
                     },
@@ -1227,11 +1237,12 @@ struct ChatView: View {
         }
     }
 
+    @discardableResult
     private func stageImportedFiles(
         _ urls: [URL],
         preferredKind: ChatMessage.Kind? = nil
-    ) async {
-        guard !urls.isEmpty else { return }
+    ) async -> Bool {
+        guard !urls.isEmpty else { return false }
         isPreparingAttachments = true
         defer { isPreparingAttachments = false }
         let prepared = await model.prepareAttachmentDrafts(
@@ -1239,10 +1250,11 @@ struct ChatView: View {
             preferredKind: preferredKind,
             for: conversation.jid
         )
-        guard !prepared.isEmpty else { return }
+        guard !prepared.isEmpty else { return false }
         model.discardAttachmentDrafts(attachmentDrafts)
         attachmentDrafts = prepared
         presentAttachmentPreviewAfterPickerDismissal()
+        return true
     }
 
     private func stageCapturedMedia(_ media: CapturedCameraMedia) async {
@@ -1251,7 +1263,10 @@ struct ChatView: View {
             photoCameraIsPreparingResult = false
             releaseArchiveSyncAfterCapture()
         }
-        await stageImportedFiles([media.url], preferredKind: media.kind)
+        let staged = await stageImportedFiles([media.url], preferredKind: media.kind)
+        if !staged, model.errorMessage == nil {
+            model.errorMessage = "Камера вернула файл, который не удалось подготовить к отправке."
+        }
     }
 
     private func presentCamera() {