Feature Request: TTY passthrough for interactive terminal applications

## Summary

Add TTY passthrough support to enable running interactive terminal applications (like Claude Code) inside the sandbox.

## Problem

When running Claude Code inside srt, the sandbox blocks TTY operations causing this error:

```
Error: setRawMode EPERM
at ReadStream.setRawMode (node:tty:81:24)
```

Claude Code requires `setRawMode` for its interactive TUI (terminal user interface). The macOS `sandbox-exec` blocks these ioctl operations.

## Current Behavior

- Simple commands work: `srt echo "hello"` ✓
- Interactive TUI apps fail: `srt claude` ✗

## Requested Behavior

Add an option to allow TTY passthrough, e.g.:

```bash
srt --tty claude
```

Or via config:

```json
{
"process": {
"allowTTY": true
}
}
```

## Use Case

Running Claude Code in a sandboxed environment where:
- Filesystem writes are restricted to the current project directory
- Network access is allowed
- But full interactive terminal UI is needed

## Environment

- macOS (sandbox-exec)
- srt version: 0.0.23
- Claude Code version: 2.0.59

## Workaround

Currently using `--print` mode for non-interactive use, but this loses the full TUI experience.