Types ForkCard/Record/Entry/List, ForkCursor and ForkLimit validated at decode, DeskRequest::Forks
gains status/cursor/limit flat, DeskResponse gains Forks and Fork, the daemon dispatches to
Mind::desk_forks/desk_fork (stubs). Vectors vendored at CultLib e57fbaee. The tests pin the rules
the next commit implements; DESK_READS_UNBUILT and its test are gone.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>