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/Runner/Interfaces/ILiveSession.cs

@@ -4,6 +4,7 @@ public interface ILiveSession : IAsyncDisposable
 {
     bool IsTurnInFlight { get; }
     Task SendUserMessageAsync(string text, CancellationToken ct);
+    Task RemoveQueuedAsync(string text, CancellationToken ct);
     Task InterruptAsync(CancellationToken ct);
     Task StopAsync();
 }

src/ClaudeDo.Worker/Runner/StreamingClaudeSession.cs

@@ -118,6 +118,35 @@ public sealed class StreamingClaudeSession : ILiveSession
             _onUserMessageSent?.Invoke(text);
     }
 
+    public async Task RemoveQueuedAsync(string text, CancellationToken ct)
+    {
+        IReadOnlyList<string>? snapshot = null;
+
+        await _sendLock.WaitAsync(ct);
+        try
+        {
+            if (_pending.Count == 0) return;
+
+            var list = _pending.ToList();
+            var idx = list.IndexOf(text);
+            if (idx < 0) return;
+
+            list.RemoveAt(idx);
+            _pending.Clear();
+            foreach (var item in list)
+                _pending.Enqueue(item);
+
+            snapshot = SnapshotPending();
+        }
+        finally
+        {
+            _sendLock.Release();
+        }
+
+        if (snapshot is not null)
+            _onQueueChanged?.Invoke(snapshot);
+    }
+
     public async Task InterruptAsync(CancellationToken ct)
     {
         await _sendLock.WaitAsync(ct);