Add `batch` command that reads a JSON array of commands from stdin
and executes them sequentially against the daemon. This avoids
per-command process startup overhead when AI agents run multi-step
browser workflows.
Supports --bail to stop on first error (default: continue all)
and --json for structured output as an array of results.
Co-authored-by: Matt Van Horn <455140+mvanhorn@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
