feat: add physically explicit narrowband MUSIC

tests/unit/contracts.test.js

@@ -40,6 +40,8 @@ function resultFrequencyObservation(scene, experiment, band, equivalentBandIds =
     localizationModel:
       experiment.beamforming?.algorithm === "gcc-phat"
         ? "band-limited-gcc-phat-geometric-lag"
+        : experiment.beamforming?.algorithm === "music"
+          ? "near-field-music-at-positive-adc-bin-frequency"
         : "spherical-steering-at-positive-adc-bin-frequency",
     originalCarrierUsed: observation.originalCarrierUsed,
     aliasOrderResolution: observation.aliased ? "not-attempted" : "not-applicable",
@@ -234,17 +236,26 @@ test("단일 tone 장면과 실험이 관계 검증을 통과한다", async () =
   assertEqual((await validateExperiment(experiment, { arrayDefinition, scene })).length, 0, "experiment issues");
 });
 
-test("세 위치 추정 알고리즘과 backend 제약을 계약이 검증한다", async () => {
+test("네 위치 추정 알고리즘과 backend 제약을 계약이 검증한다", async () => {
   const [arrayDefinition, scene, baseline] = await Promise.all([
     loadJson("/assets/array-geometries/rectangular-16x12.array.json"),
     loadJson("/assets/sample-scenes/single-tone.scene.json"),
     loadJson("/assets/sample-scenes/single-tone.experiment.json"),
   ]);
 
-  for (const algorithm of ["das", "das-phat", "gcc-phat"]) {
+  for (const algorithm of ["das", "das-phat", "gcc-phat", "music"]) {
     const experiment = structuredClone(baseline);
     experiment.beamforming.algorithm = algorithm;
-    experiment.beamforming.backend = algorithm === "gcc-phat" ? "cpu" : "auto";
+    experiment.beamforming.backend =
+      algorithm === "gcc-phat" || algorithm === "music" ? "cpu" : "auto";
+    if (algorithm === "music") {
+      experiment.frequencyBands = [
+        { id: "single-bin", minHz: 1000, maxHz: 1050, color: "#65f2bf" },
+      ];
+      experiment.beamforming.normalization = "none";
+      experiment.beamforming.musicSourceCountMethod = "fixed";
+      experiment.beamforming.musicSourceCount = 1;
+    }
     assertEqual(
       (await validateExperiment(experiment, { arrayDefinition, scene })).length,
       0,
@@ -252,6 +263,31 @@ test("세 위치 추정 알고리즘과 backend 제약을 계약이 검증한다
     );
   }
 
+  const autoWithStaleK = structuredClone(baseline);
+  autoWithStaleK.frequencyBands = [
+    { id: "single-bin", minHz: 1000, maxHz: 1050, color: "#65f2bf" },
+  ];
+  autoWithStaleK.stft.hopSize = autoWithStaleK.stft.fftSize;
+  Object.assign(autoWithStaleK.beamforming, {
+    algorithm: "music",
+    backend: "cpu",
+    normalization: "none",
+    musicSourceCountMethod: "mdl",
+    musicSourceCount: 8,
+  });
+  const smallArray = {
+    ...arrayDefinition,
+    microphones: arrayDefinition.microphones.slice(0, 4),
+  };
+  assertEqual(
+    (await validateExperiment(autoWithStaleK, {
+      arrayDefinition: smallArray,
+      scene,
+    })).length,
+    0,
+    "MDL ignores disabled stale fixed K after an array-size change",
+  );
+
   const incompatible = structuredClone(baseline);
   incompatible.beamforming.algorithm = "gcc-phat";
   incompatible.beamforming.backend = "webgpu";
@@ -271,7 +307,7 @@ test("세 위치 추정 알고리즘과 backend 제약을 계약이 검증한다
     "GCC-PHAT requires two microphones",
   );
 
-  incompatible.beamforming.algorithm = "music";
+  incompatible.beamforming.algorithm = "invented-localizer";
   issues = await validateExperiment(incompatible, { arrayDefinition, scene });
   assert(
     issues.some(({ path }) => path === "$.beamforming.algorithm"),