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>

src/bench/real.ts

@@ -36,13 +36,13 @@ const MODELS = { demucs: "models/demucs/htdemucs_6s.onnx", basicPitch: "models/b
 const SF2 = join(import.meta.dir, "../../node_modules/@coderline/alphatab/dist/soundfont/sonivox.sf2");
 const TOL = 0.05, LENIENT_TOL = 0.1;
 
-export async function runReal(opts: { runId: string; auto: boolean; root?: string; out?: string; resultsDir?: string }): Promise<RealSongResult[]> {
+export async function runReal(opts: { runId: string; auto: boolean; root?: string; out?: string; resultsDir?: string; repeatVote?: boolean }): Promise<RealSongResult[]> {
   const root = opts.root ?? "reference", out = opts.out ?? "runs", rdir = opts.resultsDir ?? "results";
   const songs = await readManifest(root);
   const pipeline = await createPipeline({
     demucs: new Uint8Array(await Bun.file(MODELS.demucs).arrayBuffer()),
     basicPitch: new Uint8Array(await Bun.file(MODELS.basicPitch).arrayBuffer()),
-  });
+  }, { repeatVote: opts.repeatVote ?? true });
   const sf2 = opts.auto ? new Uint8Array(await Bun.file(SF2).arrayBuffer()) : null;
   const results: RealSongResult[] = [];
   const skipped: SkippedSong[] = [];