no (UI) facility to disable/enable all builders for a given processor and virtualisation

I don't care whether it's via a button, or via an API, but I need to be able to do the equivalent of:

UPDATE builder SET manual=$value WHERE active=true AND builderok=true AND virtualized=$cond AND processor=$cond;

also some way to see what builders that have an active build running are in manual mode (we've dropped this info from /builders)
That is, right now I precede the above with "SELECT * from builder where manual=true and active=true and builderok=true;" to make sure I do not later set something that should have been manual to auto when I undo that.

All in all, this really wants API support, rather than buttons, I expect.

Diagnosis
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API all exists, so this should be just a matter of UI glue these days.