Correcting design 26 to match what the merged code does, and fixing issue 112's
status, which used a word the vocabulary does not have.
A claim on a seat the manifest does not itself declare is refused at registration
rather than by the parser. A module may hold a seat another module declared —
that is why ADR 0126 has a caller name the seat and not its provider — so whether
the name exists is a fact about the whole catalogue.
And a declared seat may promise nothing. That is a marker seat, and most
node-scoped seats are markers: which module is this machine's packet filter. ADR
0126's "a declared seat carries a protocol" says what a holder must satisfy, not
that every seat offers something.
`records.py` still fails on ADR 0120 resting on a proposed ADR 0112, which is not
this branch's and not mine to decide.
jschoubben
5cac268457