stencila /stencila:preview
Open a live preview of the document (or folder) in $ARGUMENTS, defaulting
to the current folder.
Use the stencila CLI path reported in session context; otherwise
${CLAUDE_PLUGIN_OPTION_STENCILA_PATH} if set, else stencila. If no CLI
is available, point the user at /stencila:doctor and stop.
NO_COLOR=1 <stencila> open [path] --yes
open starts a local preview server and opens the browser; for a folder it
opens the first index.*, main.*, or readme.* file. If the workspace
has a [site] configuration and the user wants to preview the whole site,
use NO_COLOR=1 <stencila> site preview --yes instead (live reload).
These commands serve until interrupted — run them in the background so the session is not blocked, and tell the user the local URL from the command output and that the preview updates as files change.