Feature: Sandboxed Shell/Terminal Access

[avikeid2007]

Summary

Add sandboxed shell/terminal access - the AI can execute PowerShell commands on the user's machine with explicit user approval for each command.

Motivation

Developer productivity feature. Users can ask KaiROS to check disk space, list running processes, run build commands, or inspect files without leaving the app.

Detailed Requirements

Service: ShellService.cs

public interface IShellService
{
    bool IsEnabled { get; }
    Task<ShellResult> ExecuteAsync(string command, string workingDirectory = null, int timeoutMs = 30000, CancellationToken ct = default);
}

public class ShellResult
{
    public string Command { get; set; }
    public string StandardOutput { get; set; }
    public string StandardError { get; set; }
    public int ExitCode { get; set; }
    public TimeSpan Duration { get; set; }
    public bool WasApproved { get; set; }
}

• Execute PowerShell commands via System.Diagnostics.Process
• Capture stdout, stderr, exit code
• Configurable timeout (default 30s)
• Output size limit (truncate outputs > 10KB with "[truncated]" indicator)

Security (Critical)

• All commands require explicit user approval via a confirmation ContentDialog
• Dialog shows: command text, working directory, and "Allow" / "Deny" buttons
• Optional: "Always allow" for specific command prefixes (configurable in Settings)
• Configurable allowed working directories
• Block dangerous commands by default (format, del /, rm -rf, etc.)

Chat Integration

• User types /run <command> or AI in Agent Mode requests shell execution
• Command output displayed in chat with monospace formatting (use existing code block rendering)
• Error output shown in red/warning color

Settings (SettingsView.xaml)

• "Shell Access" section:
  • Toggle: Enable/Disable shell access (disabled by default)
  • Default working directory path
  • Timeout setting (seconds)
  • Blocked command patterns list

Files to Create/Modify

• [NEW] Services/ShellService.cs + IShellService.cs
• [NEW] Models/ShellResult.cs
• [MODIFY] ViewModels/ChatViewModel.cs - /run command handling + approval dialog
• [MODIFY] Views/ChatView.xaml - command output display styling
• [MODIFY] Views/SettingsView.xaml - shell access settings

Acceptance Criteria

• Execute PowerShell commands from chat via /run prefix
• All commands require explicit user approval dialog
• Output displayed in monospace/code block format
• Timeout and output size limits enforced
• Enable/disable toggle in Settings (disabled by default)
• Dangerous commands blocked by default