fix(ui): gate queueing on an open interactive ConPTY session

A task-based ConPTY session leaves the row Idle in the DB (sessions never
touch status), so nothing stopped the queue picker from claiming it too:
CanSendToQueue ignored HasInteractiveSession, and both TasksIslandViewModel.
SendToQueueAsync and MissionControlViewModel.EnqueueTaskAsync (drag-to-queue)
wrote Status=Queued straight via EF, bypassing TaskStateService entirely and
its manual/draft-child guards. That let an autonomous claude process spawn in
the same worktree a user was hand-editing in the ConPTY pane.

Add !HasInteractiveSession to CanSendToQueue, and route both UI enqueue paths
through IWorkerClient.SetTaskStatusAsync (worker hub -> TaskStateService.
EnqueueAsync) instead of raw EF writes. The interactive-session gate itself
stays in the UI: the worker has no notion of a UI-hosted ConPTY pane.

tests/ClaudeDo.Worker.Tests/UiVm/TaskRowViewModelPlanningTests.cs

@@ -87,6 +87,21 @@ public class TaskRowViewModelPlanningTests
         Assert.True(vm.CanSendToQueue);
     }
 
+    [Fact]
+    public void OpenInteractiveSession_CannotSendToQueue()
+    {
+        // A hand-driven ConPTY session is still Idle in the DB (sessions never touch status), so
+        // this has to be gated on the UI-only HasInteractiveSession flag, not on Status.
+        var vm = MakeRow(TaskStatus.Idle);
+        Assert.True(vm.CanSendToQueue);
+
+        vm.HasInteractiveSession = true;
+        Assert.False(vm.CanSendToQueue);
+
+        vm.HasInteractiveSession = false;
+        Assert.True(vm.CanSendToQueue);
+    }
+
     [Fact]
     public void FinalizedParentWithChildren_CanQueuePlan()
     {