fix(apple): show receiver-approval modal on macOS release builds

The approval modal never appeared for a macOS sender: the receiver request
reached the core and even fired its notification, but the modal stayed hidden.

Root cause was observation, not presentation. `RootView` derived `approvals`
and `messages` as `@ObservedObject` in `init` from a freshly built `AppGraph`.
`init` runs on every view re-creation and each run makes a throwaway graph, so
those observed objects were repointed to a dead `ApprovalCoordinator` that never
receives core events — while the persisted `@StateObject graph` (and the models
wired to it) kept the live one. Debug happened not to re-init the view, so it
stayed on the live instance; release re-inits it, exposing the bug.

Move the snackbar + approval modal into an `OverlayLayer` child view that takes
the coordinator/messages as `@ObservedObject` and is constructed in `body` from
the persisted `graph`, so the subscription is always against the live instances.

While here:
- Present the approval only after any open share/QR sheet has actually finished
  dismissing (macOS can't stack sheets), driven off the sheet's real
  `onDismiss` completion via a new `AdaptiveDrawer.onDismissed` hook and
  `SendModel.shareSheetsDismissed` — no wall-clock delay.
- Move the list-level share-sheet state (`shareTargetId`) into `SendModel` so the
  approval flow can dismiss every share surface centrally.
- Add a fallback: pending receiver rows in the Receivers panel now offer an
  Approve action (`SendModel.acceptReceiver`) alongside Refuse, for the case the
  modal didn't surface.

apple/VniDrop/Features/Send/SendModel.swift

@@ -25,6 +25,11 @@ struct SendState: Equatable {
 	var selectedTransferId: UInt64?
 	var transferThumbnails: [UInt64: Data] = [:]
 	var detailPanel: TransferDetailPanel?
+	/// Transfer whose share panel is presented inline from the list context menu
+	/// (distinct from `detailPanel == .share`, which shows it from the detail view).
+	/// Held in the model — not `SendScreen` @State — so the approval flow can dismiss
+	/// it centrally before presenting its modal.
+	var shareTargetId: UInt64?
 	var receiverHistory: [ReceiverRequestModel] = []
 	var isLoadingReceivers = false
 	var isDeleteConfirmationOpen = false
@@ -56,6 +61,18 @@ final class SendModel: ObservableObject {
 	private let messages: UiMessageController
 	private var cancellables = Set<AnyCancellable>()
 
+	/// Fires *after* a share/QR sheet (the detail-view panel or the list-level share
+	/// sheet) has finished animating out. The approval flow waits on this to present
+	/// its modal on macOS, where a sheet shown while another is still dismissing is
+	/// dropped — using the real completion instead of a guessed delay.
+	private let shareSheetsDismissedSubject = PassthroughSubject<Void, Never>()
+	var shareSheetsDismissed: AnyPublisher<Void, Never> {
+		shareSheetsDismissedSubject.eraseToAnyPublisher()
+	}
+
+	/// Invoked by a share sheet's `onDismiss` completion.
+	func shareSheetDidDismiss() { shareSheetsDismissedSubject.send(()) }
+
 	init(
 		repository: CoreGateway,
 		fileSystemService: FileSystemService,
@@ -201,6 +218,17 @@ final class SendModel: ObservableObject {
 	}
 	func closeDetailPanel() { state.detailPanel = nil }
 
+	func openShareTarget(_ transferId: UInt64) { state.shareTargetId = transferId }
+	func closeShareTarget() { state.shareTargetId = nil }
+
+	/// Dismisses every share/QR surface at once — the detail-view share panel and the
+	/// list-level share sheet. Used before presenting the receiver-approval modal, so
+	/// no competing sheet is left open (macOS drops a sheet shown over another).
+	func dismissShareSheets() {
+		state.detailPanel = nil
+		state.shareTargetId = nil
+	}
+
 	func requestDeleteTransfer() { state.isDeleteConfirmationOpen = true }
 	func dismissDeleteTransfer() { if !state.isDeleting { state.isDeleteConfirmationOpen = false } }
 
@@ -257,8 +285,19 @@ final class SendModel: ObservableObject {
 	/// Uses the core's `respondReceiverRequest` (no backend change); applies to
 	/// receivers that are still pending or accepted.
 	func cancelReceiver(requestId: String) {
+		respondToReceiver(requestId: requestId, accepted: false)
+	}
+
+	/// Approves a single pending receiver by responding to its request positively.
+	/// A fallback for when the approval modal didn't surface — the pending receiver
+	/// can still be accepted from its row in the transfer's receivers panel.
+	func acceptReceiver(requestId: String) {
+		respondToReceiver(requestId: requestId, accepted: true)
+	}
+
+	private func respondToReceiver(requestId: String, accepted: Bool) {
 		Task {
-			let result = await repository.respondReceiverRequest(requestId: requestId, accepted: false, reason: nil)
+			let result = await repository.respondReceiverRequest(requestId: requestId, accepted: accepted, reason: nil)
 			switch result {
 			case .success:
 				if let transferId = state.selectedTransferId { refreshReceivers(transferId) }

apple/VniDrop/Features/Send/SendScreen.swift

@@ -7,14 +7,18 @@ struct SendScreen: View {
 	@ObservedObject var model: SendModel
 	let windowClass: WindowClass
 
-	/// Transfer whose share panel is presented inline from the list context menu.
-	@State private var shareTarget: Transfer?
 	/// Transfer pending an inline (list-level) delete confirmation.
 	@State private var deleteTarget: Transfer?
 
 	private var outgoing: [Transfer] {
 		model.coreState.transfers.filter { $0.direction == .send }
 	}
+	/// The transfer whose list-level share sheet is open, resolved from the model's
+	/// `shareTargetId` (kept in the model so the approval flow can dismiss it).
+	private var shareTarget: Transfer? {
+		guard let id = model.state.shareTargetId else { return nil }
+		return outgoing.first { $0.transferId == id }
+	}
 	private var selectedTransfer: Transfer? {
 		guard let id = model.state.selectedTransferId else { return nil }
 		return outgoing.first { $0.transferId == id }
@@ -50,9 +54,10 @@ struct SendScreen: View {
 			// composer drawer on the outer body, so the two don't clash). Opens the
 			// share panel over the list without navigating into the transfer detail.
 			.adaptiveDrawer(
-				isPresented: Binding(get: { shareTarget != nil }, set: { if !$0 { shareTarget = nil } }),
+				isPresented: Binding(get: { shareTarget != nil }, set: { if !$0 { model.closeShareTarget() } }),
 				windowClass: windowClass,
-				onDismiss: { shareTarget = nil }
+				onDismiss: model.closeShareTarget,
+				onDismissed: model.shareSheetDidDismiss
 			) {
 				if let shareTarget {
 					TransferSharePanel(model: model, transfer: shareTarget)
@@ -92,7 +97,8 @@ struct SendScreen: View {
 			.adaptiveDrawer(
 				isPresented: Binding(get: { model.state.detailPanel != nil }, set: { _ in }),
 				windowClass: windowClass,
-				onDismiss: model.closeDetailPanel
+				onDismiss: model.closeDetailPanel,
+				onDismissed: model.shareSheetDidDismiss
 			) {
 				if let panel = model.state.detailPanel {
 					DetailPanelContent(model: model, transfer: transfer, panel: panel)
@@ -127,7 +133,7 @@ struct SendScreen: View {
 					.contextMenu {
 						if transfer.ticket != nil {
 							Button {
-								shareTarget = transfer
+								model.openShareTarget(transfer.transferId)
 							} label: {
 								Label(String(localized: L10n.Transfer.shareTitle), systemSymbol: .squareAndArrowUp)
 							}

apple/VniDrop/Features/Send/TransferDetailsView.swift

@@ -142,7 +142,8 @@ struct DetailPanelContent: View {
 				loading: model.state.isLoadingReceivers,
 				events: model.coreState.events,
 				transferTotalSize: transfer.totalSize,
-				onCancel: model.cancelReceiver
+				onCancel: model.cancelReceiver,
+				onAccept: model.acceptReceiver
 			)
 		case .share:
 			TransferSharePanel(model: model, transfer: transfer)
@@ -193,6 +194,7 @@ struct ReceiverHistoryPanel: View {
 	let events: [CoreEventModel]
 	let transferTotalSize: UInt64
 	let onCancel: (String) -> Void
+	let onAccept: (String) -> Void
 
 	var body: some View {
 		PanelContainer(title: String(localized: L10n.Transfer.receiversTitle)) {
@@ -203,7 +205,12 @@ struct ReceiverHistoryPanel: View {
 			} else {
 				ForEach(Array(receivers.enumerated()), id: \.element.id) { index, receiver in
 					if index > 0 { Divider().overlay(colors.borderDefault) }
-					ReceiverRow(receiver: receiver, sendProgress: sendProgress(for: receiver), onCancel: onCancel)
+					ReceiverRow(
+						receiver: receiver,
+						sendProgress: sendProgress(for: receiver),
+						onCancel: onCancel,
+						onAccept: onAccept
+					)
 				}
 			}
 		}
@@ -224,6 +231,7 @@ private struct ReceiverRow: View {
 	let receiver: ReceiverRequestModel
 	let sendProgress: TransferProgress?
 	let onCancel: (String) -> Void
+	let onAccept: (String) -> Void
 
 	/// Only pending requests can be cancelled per-receiver: the core rejects a
 	/// negative response to an already-accepted request ("...not approved, or it
@@ -257,14 +265,27 @@ private struct ReceiverRow: View {
 			}
 			.frame(maxWidth: .infinity, alignment: .leading)
 			if isCancelable {
-				Button(role: .destructive) {
-					onCancel(receiver.id)
-				} label: {
-					Text(String(localized: L10n.Button.refuse))
-						.font(VniType.bodySmall)
+				VStack(alignment: .trailing, spacing: 8) {
+					Button(role: .destructive) {
+						onCancel(receiver.id)
+					} label: {
+						Text(String(localized: L10n.Button.refuse))
+							.font(VniType.bodySmall)
+					}
+					.buttonStyle(.borderless)
+					.tint(.red)
+					// Fallback approve action, in case the approval modal didn't surface.
+					Button {
+						onAccept(receiver.id)
+					} label: {
+						Text(String(localized: L10n.Button.approve))
+							.font(VniType.bodySmall).fontWeight(.medium)
+							.foregroundStyle(.white)
+							.padding(.horizontal, 16).padding(.vertical, 7)
+							.background(Color.green, in: Capsule())
+					}
+					.buttonStyle(.plain)
 				}
-				.buttonStyle(.borderless)
-				.tint(.red)
 			}
 		}
 		.frame(maxWidth: .infinity, alignment: .leading)