feat(worker): remove a queued interactive message

StreamingClaudeSession.RemoveQueuedAsync drops the first occurrence of a queued
message from _pending and re-broadcasts the updated queue. Wired through
InteractiveSessionService + WorkerHub.RemoveQueuedInteractiveMessage +
IWorkerClient.RemoveQueuedInteractiveMessageAsync. Removal by text (first match)
is robust to a turn flushing mid-click. Fakes + ILiveSession impls updated.

src/ClaudeDo.Worker/Planning/InteractiveSessionService.cs

@@ -127,6 +127,12 @@ public sealed class InteractiveSessionService
         await session.SendUserMessageAsync(text, ct);
     }
 
+    public async Task RemoveQueuedAsync(string taskId, string text, CancellationToken ct)
+    {
+        if (_registry.TryGet(taskId, out var session))
+            await session.RemoveQueuedAsync(text, ct);
+    }
+
     public async Task InterruptAsync(string taskId, CancellationToken ct)
     {
         if (_registry.TryGet(taskId, out var session))