Fix crash when adding drawing attachment

Packages/ComposeUI/Sources/ComposeUI/Controllers/AttachmentsListController.swift

@@ -96,14 +96,17 @@ class AttachmentsListController: ViewController {
     }
     
     private func addImage() {
+        parent.deleteDraftOnDisappear = false
         parent.config.presentAssetPicker?({ results in
             self.insertAttachments(at: self.draft.attachments.count, itemProviders: results.map(\.itemProvider))
         })
     }
     
     private func addDrawing() {
+        parent.deleteDraftOnDisappear = false
         parent.config.presentDrawing?(PKDrawing()) { drawing in
             let attachment = DraftAttachment(context: DraftsPersistentContainer.shared.viewContext)
+            attachment.id = UUID()
             attachment.drawing = drawing
             attachment.draft = self.draft
             self.draft.attachments.add(attachment)

Packages/ComposeUI/Sources/ComposeUI/Controllers/ComposeController.swift

@@ -208,6 +208,7 @@ public final class ComposeController: ViewController {
             do {
                 try await poster.post()
                 
+                deleteDraftOnDisappear = true
                 didPostSuccessfully = true
                 
                 // wait .25 seconds so the user can see the progress bar has completed