Global Settings: MIDI/Tempo: add Snapshot CC Send (135)

[rtsai]

Inadvertent omission from #16

[john-baxter-dev]

Landed on master as c5a9105 — thank you. Closing by hand rather than by button: master had moved a
commit ahead of your branch, so this got replayed onto it and GitHub can't match the new SHA to
faad934. Your authorship is on the commit.

MENU_ORDER is complete with this. Every identified id outside Global EQ now has a menu position,
which it hasn't since the table existed.

One thing worth saying out loud, because the diff hides it. Rows sort by
(group_rank, menu_rank, id) and an unplaced id ranks past the end, so 135 was already drawing
at the foot of MIDI/Tempo — exactly where row 10 puts it. Nothing moved on screen. What changed is
that the position is now a reading rather than a fallback, and that's only true if you actually
looked at the pedal. If you appended it from the list in the issue instead, say so and I'll put the
fallback back — a guess that happens to be right is still a guess here, and it'd be filed as
observed. No wrong answer, I just can't tell from the diff.

Follow-up in 8084968, nothing that changes your entry:

only_the_listed_ids_are_unplaced failed on your PR, which is the test doing its job in a way I
didn't anticipate. I added it last round to catch the next id arriving without a position; what it
caught first was the answer arriving for this one, because it asserts the unplaced set equals
&[135] rather than merely contains it. That's the version worth having — the loose form would have
let the discovery sheet, the mock and three paragraphs of prose sit stale and green. UNPLACED is
&[] now.

Also mirrored the order into ui/src/mock/backend.js (it keeps its own copy for npm run dev), and
retired the question in _TODO-settings-names.md. That sheet is down to two open items, neither of
them yours: whether any of the 19 XL ids refuse on a Stomp, which needs my pedal, and the
95/96/68/69 Preferences re-check.

[rtsai]

Yes, setting 135 is indeed the 10th item in the "MIDI/Tempo" Global Settings HX UI. Thank you!

and the 95/96/68/69 Preferences re-check.

If this is about Kind::Flag vs Kind::Choice, I believe settings.rs is currently correct at 8084968; settings-dump shows them as they are in settings.rs