A server confined with --automation-read-root or
--automation-write-root has no plug-in store, so a grant accepted under
the flag could not be written to grants.json and recorded grants were
not read. mcp now refuses the combination at start-up.
The help text, docs/plugins.md and docs/mcp.md state that a confined
server does not install a module that lists permissions or asks for a
heavy budget, and that with VECTORCRAFT_NO_PREFS set a grant accepted
under the flag lasts for that session only.