Process launch with context cancellation, socket directory auto-creation,
channel-based stop synchronization. Uses sleep as fake Deno in tests.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Options, Permissions with Deno --allow-* flag generation,
DefaultSocketPath with XDG_RUNTIME_DIR support, Sidecar struct.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>