perf(lab): stream sealed spatial playback tracks

apps/control-station/test/m49TgsFullShadow.test.mjs

@@ -6,6 +6,7 @@ import { createServer } from "vite";
 
 let server;
 let fetchM49TgsFullShadowSpatialChunk;
+let parseM49TgsNpyTrack;
 
 const resultId = `m49-tgs-full-shadow-${"a".repeat(64)}`;
 
@@ -15,7 +16,7 @@ before(async () => {
     logLevel: "silent",
     server: { middlewareMode: true },
   });
-  ({ fetchM49TgsFullShadowSpatialChunk } = await server.ssrLoadModule(
+  ({ fetchM49TgsFullShadowSpatialChunk, parseM49TgsNpyTrack } = await server.ssrLoadModule(
     "/src/core/laboratory/m49TgsFullShadow.ts",
   ));
 });
@@ -73,7 +74,7 @@ test("M4.9T5 chunk keeps every missing-LiDAR cell explicitly UNOBSERVED", async
   assert.deepEqual(new Set(chunk.frames[0].costmap.states), new Set([0]));
 });
 
-test("M4.9T5 viewer prefetches 24-frame immutable chunks", async () => {
+test("M4.9T5 viewer preloads one immutable binary playback pack", async () => {
   const [source, contract] = await Promise.all([
     readFile(
       new URL("../src/workspaces/laboratory/M49TgsFullShadowEvidence.tsx", import.meta.url),
@@ -84,12 +85,37 @@ test("M4.9T5 viewer prefetches 24-frame immutable chunks", async () => {
       "utf8",
     ),
   ]);
-  assert.match(source, /const CHUNK_FRAMES = 24/);
-  assert.match(source, /activeChunkStart \+ CHUNK_FRAMES/);
-  assert.match(source, /fetchM49TgsFullShadowSpatialChunk/);
+  assert.match(source, /fetchM49TgsFullShadowPlaybackPack/);
+  assert.match(source, /playbackProgress/);
+  assert.doesNotMatch(source, /fetchM49TgsFullShadowSpatialChunk/);
   assert.match(source, /sampleAvailable: spatial\.sampleAvailable/);
   assert.match(source, /fetchE47SemanticSlamResult/);
   assert.match(source, /next\.baseM4ResultId !== result\.source\.linkedVisualResultId/);
   assert.match(source, /semantic=\{semantic \? \{/);
   assert.match(contract, /linked_semantic_result_id/);
+  assert.match(contract, /missioncore\.m49-tgs-full-shadow-playback\/v1/);
+});
+
+function npyFloat32(values, shape) {
+  const shapeText = shape.length === 1 ? `${shape[0]},` : shape.join(", ");
+  const prefixLength = 10;
+  let header = `{'descr': '<f4', 'fortran_order': False, 'shape': (${shapeText}), }`;
+  const padding = (16 - ((prefixLength + header.length + 1) % 16)) % 16;
+  header += " ".repeat(padding) + "\n";
+  const buffer = new ArrayBuffer(prefixLength + header.length + values.length * 4);
+  const bytes = new Uint8Array(buffer);
+  bytes.set([0x93, 0x4e, 0x55, 0x4d, 0x50, 0x59, 1, 0]);
+  new DataView(buffer).setUint16(8, header.length, true);
+  bytes.set(new TextEncoder().encode(header), prefixLength);
+  new Float32Array(buffer, prefixLength + header.length, values.length).set(values);
+  return buffer;
+}
+
+test("M4.9T5 parses sealed NPY tracks without JSON point arrays", () => {
+  const parsed = parseM49TgsNpyTrack(
+    npyFloat32([1.25, -2.5, 3.75, 4.5], [2, 2]),
+    "<f4",
+    [2, 2],
+  );
+  assert.deepEqual([...parsed], [1.25, -2.5, 3.75, 4.5]);
 });