fix(pipeline): repeat-vote review fixes

- Return an unchanged copy for a non-finite/zero grid (NaN downbeat used to
  delete every guitar note).
- Skip an added note when a same-pitch note (bar, neighbouring bars or already
  added) lies within tol; avoids near-duplicates across bar lines.
- bench run/real: --no-repeat-vote passes { repeatVote: false } to the pipeline.
- Tests: notes before a late downbeat, bpm 0 / NaN / Infinity, trailing partial
  bar, half-tempo grid, neighbour-bar duplicate, pipeline-level on/off.

Eval unchanged: synthetic t1a 0.885 t1b 0.840 t1c 0.752 t1d 0.737, lnoe 0.507.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/pipeline/repeat.test.ts

@@ -41,9 +41,53 @@ test("add/drop can be disabled and empty input is handled", () => {
   expect(repeatVote([], grid)).toEqual([]);
 });
 
-test("bars before a late first downbeat are handled", () => {
-  const g: Grid = { ...grid, firstDownbeat: 0.5 };
-  const notes = bars(6, (b, pos) => !(b === 2 && pos === 0.5)).map((n) => ({ ...n, onset: n.onset + 0.5, offset: n.offset + 0.5 }));
+test("notes before a late first downbeat are voted too", () => {
+  // Grid downbeat at 4.3 s; the riff starts at 0.3 s, so bars -2 and -1 precede the first downbeat.
+  const g: Grid = { ...grid, firstDownbeat: 4.3 };
+  const notes = bars(6, (b, pos) => !(b === 0 && pos === 0.5)).map((n) => ({ ...n, onset: n.onset + 0.3, offset: n.offset + 0.3 }));
+  expect(notes[0]!.onset).toBeLessThan(g.firstDownbeat);
   const out = repeatVote(notes, g);
-  expect(out.some((n) => Math.abs(n.onset - 5) < 1e-6 && n.pitch === 55)).toBe(true);
+  expect(out.length).toBe(30);
+  expect(out.some((n) => Math.abs(n.onset - 0.8) < 1e-6 && n.pitch === 55)).toBe(true);
+});
+
+test("non-finite or zero grid returns an unchanged copy", () => {
+  const notes = bars(6, (b, pos) => !(b === 3 && pos === 1));
+  for (const g of [
+    { ...grid, bpm: 0 }, { ...grid, bpm: NaN }, { ...grid, bpm: Infinity },
+    { ...grid, firstDownbeat: NaN }, { ...grid, firstDownbeat: -Infinity }, { ...grid, beatsPerBar: NaN },
+  ]) {
+    const out = repeatVote(notes, g);
+    expect(out).toEqual(notes);
+    expect(out).not.toBe(notes);
+  }
+});
+
+test("notes after the last full bar are kept and voted", () => {
+  // 6 full bars plus a trailing partial bar holding only the riff's first note.
+  const notes = [...bars(6), { onset: 12, offset: 12.2, pitch: 52 }];
+  const out = repeatVote(notes, grid);
+  // Every input note survives (the trailing one is supported by the riff's downbeat note in all repeats) ...
+  for (const n of notes) expect(out.some((m) => Math.abs(m.onset - n.onset) < 1e-6 && m.pitch === n.pitch)).toBe(true);
+  // ... and anything added there stays inside that bar.
+  expect(out.every((n) => n.onset < 14)).toBe(true);
+});
+
+test("half-tempo grid (riff twice per bar) still fills a missing note", () => {
+  const g: Grid = { ...grid, bpm: 60 }; // 4 s bars
+  const notes = bars(8, (b, pos) => !(b === 5 && pos === 1));
+  const out = repeatVote(notes, g);
+  expect(out.some((n) => Math.abs(n.onset - 11) < 1e-6 && n.pitch === 57)).toBe(true);
+});
+
+test("added notes do not duplicate a same-pitch note within tol in a neighbouring bar", () => {
+  // The riff ends with a note 80 ms before the next downbeat. In bar 3 that note is 40 ms late, which moves it
+  // across the bar line into bar 4: bar 3 looks like it misses the note, but adding it would duplicate the late one.
+  const notes = bars(6).flatMap((n) => n.pitch === 52 ? [n, { onset: n.onset + 1.92, offset: n.onset + 2, pitch: 64 }] : [n])
+    .map((n) => (n.pitch === 64 && Math.abs(n.onset - 7.92) < 1e-9 ? { ...n, onset: 7.96, offset: 8.04 } : n));
+  const out = repeatVote(notes, grid, { drop: false });
+  expect(out.filter((n) => n.pitch === 64 && Math.abs(n.onset - 7.94) < 0.1).length).toBe(1);
+  // Without the late note, the gap is filled.
+  const gap = notes.filter((n) => !(n.pitch === 64 && n.onset === 7.96));
+  expect(repeatVote(gap, grid, { drop: false }).some((n) => n.pitch === 64 && Math.abs(n.onset - 7.92) < 1e-6)).toBe(true);
 });