a02957034d
Second half of the printer/relay decoupling: the category section's
add-button gate ("add a controller first — a printer points at one of
its relays") blocked every non-access category while zero controllers
existed — hit on the lab bench (USB printer test, no relays on hand).
Printers don't bind (role + failoverRank route jobs), so the gate now
exempts them like the form's requirement already does.
Claude-Session: https://claude.ai/code/session_01Xcm6ikLgGoCxxHrxtjkk5V