fix: complete legacy operator parity workflows

src/MBN_STOCK_WEBVIEW.LegacyParityApp/MainWindow.Playout.cs

@@ -686,7 +686,8 @@ public sealed partial class MainWindow
         // independent of the scheduler remaining active between refreshes. All
         // uncertain/pending/busy states below remain fail-closed.
         var isSafeCutTailAppend = intent is
-            LegacyCutPointerDownIntent { AllowAppend: true };
+            LegacyCutPointerDownIntent { AllowAppend: true } or
+            LegacyDropSelectedCutsIntent;
         // MainForm kept its Space and "all" enabled-state gestures available while
         // PROGRAM was active. They only change the native operator playlist; NEXT
         // stops the refresh loop before the workflow adopts those flags. Therefore
@@ -694,8 +695,26 @@ public sealed partial class MainWindow
         var isSafeProgramEnabledStateMutation = intent is
             LegacySetAllPlaylistEnabledIntent or
             LegacyToggleActivePlaylistEnabledIntent;
+        // Deleting selected rows is also independent of the refresh scheduler, but
+        // only after the exact current row and every selected index are checked by
+        // CanDeleteSelectedPlaylistTail below. The one-slot ordered UI gate keeps
+        // this request behind its preceding row selection without allowing repeats.
+        var isSafeProgramTailDelete = intent is
+            LegacyDeleteSelectedPlaylistRowsIntent;
+        // PList did not stop or replace the active scene when it created, saved,
+        // overwrote, or deleted a named DB playlist. These writes only persist a
+        // snapshot/definition and are serialized with the automatic refresh by the
+        // shared intent and database gates. Loading remains an idle-only structural
+        // replacement below.
+        var isSafeNamedPlaylistPersistenceMutation = intent is
+            LegacyCreateNamedPlaylistIntent or
+            LegacySaveCurrentNamedPlaylistIntent or
+            LegacySaveCurrentNamedPlaylistToIntent or
+            LegacyDeleteSelectedNamedPlaylistIntent;
         var refreshAllowsMutation = isSafeCutTailAppend ||
             isSafeProgramEnabledStateMutation ||
+            isSafeProgramTailDelete ||
+            isSafeNamedPlaylistPersistenceMutation ||
             (!refresh.IsActive && (_refreshTask is null || _refreshTask.IsCompleted));
         var runtimeAcceptsIndependentMutation = Volatile.Read(ref _playoutBusy) == 0 &&
             Volatile.Read(ref _playoutQuarantined) == 0 &&
@@ -711,6 +730,14 @@ public sealed partial class MainWindow
             return false;
         }
 
+        if (isSafeCutTailAppend &&
+            !CanAppendCutToPlaylistTail(status, workflow))
+        {
+            rejectionMessage =
+                "PROGRAM 상태에서는 현재 송출 행을 확인할 수 있을 때만 새 컷을 대기열 끝에 추가할 수 있습니다.";
+            return false;
+        }
+
         if (RequiresIdlePlaylistMutation(intent) && !IsPlaylistMutationIdle(status, workflow))
         {
             rejectionMessage = intent is
@@ -740,6 +767,39 @@ public sealed partial class MainWindow
         return true;
     }
 
+    private bool CanAppendCutToPlaylistTail(
+        PlayoutStatus status,
+        LegacyPlayoutWorkflowState workflow)
+    {
+        if (IsPlaylistMutationIdle(status, workflow))
+        {
+            return true;
+        }
+
+        // SetPlayList in MainForm always inserted after RowCount. Keep that PROGRAM
+        // behavior only while the native playlist still has one exact on-air anchor;
+        // the newly appended row is then guaranteed to be in the future tail.
+        if (string.IsNullOrWhiteSpace(status.OnAirSceneName) ||
+            string.IsNullOrWhiteSpace(workflow.OnAirCutCode) ||
+            string.IsNullOrWhiteSpace(workflow.CurrentEntryId) ||
+            workflow.CurrentCueIndexZeroBased < 0)
+        {
+            return false;
+        }
+
+        var playlist = _controller.Current.Playlist;
+        var currentIndex = workflow.CurrentCueIndexZeroBased;
+        return currentIndex < playlist.Count &&
+            string.Equals(
+                playlist[currentIndex].RowId,
+                workflow.CurrentEntryId,
+                StringComparison.Ordinal) &&
+            playlist.Count(row => string.Equals(
+                row.RowId,
+                workflow.CurrentEntryId,
+                StringComparison.Ordinal)) == 1;
+    }
+
     private static bool RequiresIdlePlaylistMutation(LegacyUiIntent intent) => intent is
         LegacySetPlaylistEnabledIntent or
         LegacyMoveSelectedPlaylistRowsIntent or