feat(worker): broadcast interactive message queue + delivery

StreamingClaudeSession raises onQueueChanged (pending snapshot) and onUserMessageSent
(on delivery, incl. the seeded first prompt); InteractiveSessionService forwards these
as InteractiveQueueChanged/InteractiveMessageSent broadcasts. Lets the UI show queued
messages above the input and move a message into the transcript only when actually
delivered to Claude. Client events + fakes updated.

src/ClaudeDo.Worker/Hub/HubBroadcaster.cs

@@ -83,4 +83,10 @@ public sealed class HubBroadcaster : IPrimeBroadcaster, IRefineBroadcaster
 
     public Task InteractiveSessionEnded(string taskId) =>
         _hub.Clients.All.SendAsync("InteractiveSessionEnded", taskId);
+
+    public Task InteractiveQueueChanged(string taskId, IReadOnlyList<string> pending) =>
+        _hub.Clients.All.SendAsync("InteractiveQueueChanged", taskId, pending);
+
+    public Task InteractiveMessageSent(string taskId, string text) =>
+        _hub.Clients.All.SendAsync("InteractiveMessageSent", taskId, text);
 }

src/ClaudeDo.Worker/Planning/InteractiveSessionService.cs

@@ -88,7 +88,9 @@ public sealed class InteractiveSessionService
             var streamingSession = new StreamingClaudeSession(
                 transport,
                 onLine,
-                _loggerFactory.CreateLogger<StreamingClaudeSession>());
+                _loggerFactory.CreateLogger<StreamingClaudeSession>(),
+                onQueueChanged: pending => _ = _broadcaster.InteractiveQueueChanged(taskId, pending),
+                onUserMessageSent: text => _ = _broadcaster.InteractiveMessageSent(taskId, text));
             await streamingSession.StartAsync(args, workingDir, seededPrompt, ct);
             session = streamingSession;
             exitTask = transport.WaitForExitAsync();

src/ClaudeDo.Worker/Runner/StreamingClaudeSession.cs

@@ -8,6 +8,8 @@ public sealed class StreamingClaudeSession : ILiveSession
     private readonly IClaudeStreamTransport _transport;
     private readonly Func<string, Task> _onLine;
     private readonly ILogger<StreamingClaudeSession> _logger;
+    private readonly Action<IReadOnlyList<string>>? _onQueueChanged;
+    private readonly Action<string>? _onUserMessageSent;
 
     private readonly SemaphoreSlim _sendLock = new(1, 1);
     private volatile bool _isTurnInFlight;
@@ -18,13 +20,19 @@ public sealed class StreamingClaudeSession : ILiveSession
     public StreamingClaudeSession(
         IClaudeStreamTransport transport,
         Func<string, Task> onLine,
-        ILogger<StreamingClaudeSession> logger)
+        ILogger<StreamingClaudeSession> logger,
+        Action<IReadOnlyList<string>>? onQueueChanged = null,
+        Action<string>? onUserMessageSent = null)
     {
         _transport = transport;
         _onLine = onLine;
         _logger = logger;
+        _onQueueChanged = onQueueChanged;
+        _onUserMessageSent = onUserMessageSent;
     }
 
+    private IReadOnlyList<string> SnapshotPending() => _pending.ToArray();
+
     public async Task StartAsync(
         IReadOnlyList<string> args,
         string workingDirectory,
@@ -34,6 +42,7 @@ public sealed class StreamingClaudeSession : ILiveSession
         _transport.LineReceived += HandleLineAsync;
         await _transport.StartAsync(args, workingDirectory, ct);
         await SendTurnAsync(firstPrompt, ct);
+        _onUserMessageSent?.Invoke(firstPrompt);
     }
 
     private async Task HandleLineAsync(string line)
@@ -53,30 +62,45 @@ public sealed class StreamingClaudeSession : ILiveSession
         if (!isResult) return;
 
         // Turn ended — flush one queued message if available.
+        string? flushedText = null;
+        IReadOnlyList<string>? remainingSnapshot = null;
+
         await _sendLock.WaitAsync();
         try
         {
             _isTurnInFlight = false;
             if (_pending.Count > 0)
             {
-                var next = _pending.Dequeue();
-                await SendTurnAsync(next, CancellationToken.None);
+                flushedText = _pending.Dequeue();
+                remainingSnapshot = SnapshotPending();
+                await SendTurnAsync(flushedText, CancellationToken.None);
             }
         }
         finally
         {
             _sendLock.Release();
         }
+
+        if (flushedText is not null)
+        {
+            _onQueueChanged?.Invoke(remainingSnapshot!);
+            _onUserMessageSent?.Invoke(flushedText);
+        }
     }
 
     public async Task SendUserMessageAsync(string text, CancellationToken ct)
     {
+        bool enqueued = false;
+        IReadOnlyList<string>? snapshot = null;
+
         await _sendLock.WaitAsync(ct);
         try
         {
             if (_isTurnInFlight || _pending.Count > 0)
             {
                 _pending.Enqueue(text);
+                snapshot = SnapshotPending();
+                enqueued = true;
             }
             else
             {
@@ -87,6 +111,11 @@ public sealed class StreamingClaudeSession : ILiveSession
         {
             _sendLock.Release();
         }
+
+        if (enqueued)
+            _onQueueChanged?.Invoke(snapshot!);
+        else
+            _onUserMessageSent?.Invoke(text);
     }
 
     public async Task InterruptAsync(CancellationToken ct)