Run Server Command

Runs a shell command on the user's own hosting server (npm install, static builds, file ops). No SFTP/SSH client or credentials are required. Runs sandboxed in their isolated container. `site` = the key or domain of an EXTRA website on that server; the command then runs inside that website's folder (this is how you run `node seo-check.mjs` or a build for a second site). Leave it empty for the server's main website.

A foreground command must finish in about 2.5 minutes; a tool call cannot stay open longer than that, whatever timeout_s says. For anything slower (npm install, an image pipeline, a full site build) pass background=true: the command keeps running on the server after the call returns and you get a job id back, which site_command_status turns into the live output and the exit code. That is the way to install packages; a foreground `npm install` of anything sizeable will be cut off.