scoreview-engine v4.7.5-engine.5

release v4.7.5-engine.5

Metadata gains measureFacts and a tick per noteSpellings entry. ScoreView
wants beats per measure for its metronome and for beat numbers over the
notes, and had to estimate them from a measure's duration and the quarter
tempo - which cannot tell 6/8 from 3/4 and miscounts a pickup. The position
export says when a measure starts, not what it is; the time signature per
measure can only come from here.

measureFacts lists every notated measure as {measure, tick, sigN, sigD,
ticks}: the nominal signature it was laid out with and its actual length,
so a pickup (shorter) and an irregular measure (longer) are visible as
such. Same numbering as keySigs - score order, repeats not unrolled, 480
ticks per quarter; consecutive entries are contiguous.

noteSpellings entries carry the segment's notated tick on the same scale,
so "where in its measure does this chord stand" is one subtraction, exact,
without a detour through milliseconds and tempo.

Checked on a hand-written score with a one-quarter pickup, a 3/4 and a 6/8
measure (480, 1920, 1440, 1440 ticks) and on the key-signature fixture. The
corpus comparison against the frozen Qt baseline allows the new key; native
and wasm still compare it exactly. The MuseScore core stays unpatched.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HR7wyuvffSuWkRYxv9D5kL