chore(plan): triage the last two decision tickets, and correct a stale record

Rule-14 sweep, closing pass.

#2199 -> needs_user. Its note ends "/rv/tmp/runtime/ ABSENT. CNA and
mobile-eggbert were not inspected", and both are stale -- but neither was
ever its gate. The two real gates stand: the XObject layout growth is exactly
what the user declined for #1896, and remove_Changed cannot identify a
registration because std::function is not equality-comparable, which the
reference cannot settle since .NET's delegates are. Both questions recorded.

#2384 -> needs_user. Its own note already said "blocked on the decision
itself, not on evidence". How much of .NET's surface to carry is a scope
decision, and SA-5 explicitly does not license inventing or omitting surface
on judgement. Both branches of its criteria are recorded, with the note that
#2382 has already made Half and BFloat16 symmetric and either branch must
keep them so.

Author: robertvokac