feat: Add CommandTool for user-approved shell command execution, integrating it with a custom spinner that can be paused during interaction.

Program.cs

@@ -239,10 +239,50 @@ while (true)
         }
 
         // Phase 1: Show BouncingBar spinner while agent thinks & invokes tools
-        await AnsiConsole.Status()
-            .Spinner(Spinner.Known.BouncingBar)
-            .SpinnerStyle(Style.Parse("cornflowerblue"))
-            .StartAsync("Thinking...", async ctx =>
+        using var spinnerCts = CancellationTokenSource.CreateLinkedTokenSource(responseCts.Token);
+        bool showSpinner = true;
+        
+        CommandTool.PauseSpinner = () => 
+        { 
+            showSpinner = false; 
+            Console.Write("\r" + new string(' ', 40) + "\r"); 
+        };
+        CommandTool.ResumeSpinner = () => 
+        { 
+            showSpinner = true; 
+        };
+
+        var spinnerTask = Task.Run(async () =>
+        {
+            var frames = Spinner.Known.BouncingBar.Frames;
+            var interval = Spinner.Known.BouncingBar.Interval;
+            int i = 0;
+            
+            // Hide cursor
+            Console.Write("\x1b[?25l");
+            try
+            {
+                while (!spinnerCts.Token.IsCancellationRequested)
+                {
+                    if (showSpinner)
+                    {
+                        var frame = frames[i % frames.Count];
+                        Console.Write($"\r\x1b[38;5;69m{frame}\x1b[0m Thinking...");
+                        i++;
+                    }
+                    try { await Task.Delay(interval, spinnerCts.Token); } catch { }
+                }
+            }
+            finally
+            {
+                // Clear the spinner line and show cursor
+                if (showSpinner)
+                    Console.Write("\r" + new string(' ', 40) + "\r");
+                Console.Write("\x1b[?25h");
+            }
+        });
+
+        try
         {
             while (await stream.MoveNextAsync())
             {
@@ -252,10 +292,17 @@ while (true)
                 {
                     firstChunk = stream.Current.Text;
                     fullResponse = firstChunk;
-                        return; // Break out → stops the spinner
+                    break;
                 }
             }
-            });
+        }
+        finally
+        {
+            spinnerCts.Cancel();
+            await Task.WhenAny(spinnerTask);
+            CommandTool.PauseSpinner = null;
+            CommandTool.ResumeSpinner = null;
+        }
 
         // Phase 2: Stream text tokens directly to the console
         if (firstChunk != null)

Tools/CommandTool.cs

@@ -10,6 +10,8 @@ namespace AnchorCli.Tools;
 internal static class CommandTool
 {
     public static Action<string> Log { get; set; } = Console.WriteLine;
+    public static Action? PauseSpinner { get; set; }
+    public static Action? ResumeSpinner { get; set; }
 
 #if WINDOWS
     [Description("Execute a PowerShell command after user approval. Prompts with [Y/n] before running. Note: For file editing and operations, use the built-in file tools (ReadFile, ReplaceLines, InsertAfter, DeleteRange, CreateFile, etc.) instead of shell commands.")]
@@ -22,6 +24,9 @@ internal static class CommandTool
         Log($"Command request: {command}");
 
         // Prompt for user approval
+        PauseSpinner?.Invoke();
+        try
+        {
             AnsiConsole.WriteLine();
             AnsiConsole.Write(
                 new Panel($"[yellow]{Markup.Escape(command)}[/]")
@@ -31,14 +36,23 @@ internal static class CommandTool
                     .Padding(1, 0));
 
             // Drain any buffered keystrokes so stale input doesn't auto-answer
+            try
+            {
                 while (Console.KeyAvailable)
                     Console.ReadKey(intercept: true);
+            }
+            catch { }
 
             if (!AnsiConsole.Confirm("Execute?", defaultValue: true))
             {
                 AnsiConsole.MarkupLine("[dim grey]  ✗ Cancelled by user[/]");
                 return "ERROR: Command execution cancelled by user";
             }
+        }
+        finally
+        {
+            ResumeSpinner?.Invoke();
+        }
 
         // Execute the command
         try