perf(lab): stream sealed spatial playback tracks

apps/control-station/src/core/laboratory/m49TgsFullShadow.ts

@@ -84,6 +84,48 @@ export interface M49TgsFullShadowSpatialChunk {
   frames: readonly M49TgsFullShadowSpatial[];
 }
 
+export type M49TgsFullShadowPlaybackTrackId =
+  | "frames"
+  | "centers"
+  | "states"
+  | "z-bounds";
+
+export interface M49TgsFullShadowPlaybackProgress {
+  phase: "manifest" | "download" | "verify" | "ready";
+  trackId: M49TgsFullShadowPlaybackTrackId | null;
+  loadedBytes: number;
+  totalBytes: number;
+}
+
+interface M49TgsFullShadowPlaybackTrack {
+  id: M49TgsFullShadowPlaybackTrackId;
+  url: string;
+  mediaType: string;
+  dtype: "ndjson" | "<f4" | "|u1";
+  shape: readonly number[];
+  byteLength: number;
+  sha256: string;
+}
+
+export interface M49TgsFullShadowPlaybackFrame {
+  sourceSequence: number;
+  sourceFrameIndex: number;
+  sessionSeconds: number;
+  sampleAvailable: boolean;
+  metrics: M49TgsFullShadowSpatial["metrics"];
+}
+
+export interface M49TgsFullShadowPlaybackPack {
+  resultId: string;
+  frameCount: 4489;
+  cellCount: 2244;
+  totalByteLength: number;
+  centersXyM: readonly (readonly [number, number])[];
+  states: Uint8Array;
+  zBoundsM: Float32Array;
+  frames: readonly M49TgsFullShadowPlaybackFrame[];
+}
+
 export class M49TgsFullShadowContractError extends Error {}
 
 function objectValue(value: unknown, label: string): Record<string, unknown> {
@@ -335,3 +377,285 @@ export async function fetchM49TgsFullShadowSpatialChunk(
     )),
   };
 }
+
+function playbackTrackId(value: unknown, label: string): M49TgsFullShadowPlaybackTrackId {
+  const parsed = text(value, label);
+  if (parsed !== "frames" && parsed !== "centers" && parsed !== "states" && parsed !== "z-bounds") {
+    throw new M49TgsFullShadowContractError(`${label}: неизвестная playback-дорожка.`);
+  }
+  return parsed;
+}
+
+function playbackDtype(value: unknown, label: string): M49TgsFullShadowPlaybackTrack["dtype"] {
+  const parsed = text(value, label);
+  if (parsed !== "ndjson" && parsed !== "<f4" && parsed !== "|u1") {
+    throw new M49TgsFullShadowContractError(`${label}: неизвестный dtype.`);
+  }
+  return parsed;
+}
+
+function playbackShape(value: unknown, label: string): readonly number[] {
+  if (!Array.isArray(value) || !value.length) {
+    throw new M49TgsFullShadowContractError(`${label}: ожидалась размерность.`);
+  }
+  return value.map((item, index) => integer(item, `${label}.${index}`));
+}
+
+async function fetchPlaybackManifest(
+  id: string,
+  fetcher: LaboratoryFetch,
+  signal: AbortSignal | undefined,
+): Promise<{
+  frameCount: 4489;
+  cellCount: 2244;
+  totalByteLength: number;
+  tracks: ReadonlyMap<M49TgsFullShadowPlaybackTrackId, M49TgsFullShadowPlaybackTrack>;
+}> {
+  const response = await fetcher(
+    `/api/v1/laboratory/m49/tgs-full-shadow/${encodeURIComponent(id)}/playback/manifest`,
+    { method: "GET", headers: { Accept: "application/json" }, signal },
+  );
+  if (!response.ok) {
+    throw new M49TgsFullShadowContractError(`M49 playback manifest недоступен: HTTP ${response.status}.`);
+  }
+  const payload = objectValue(await response.json(), "M49 playback manifest");
+  exact(payload.schema_version, "missioncore.m49-tgs-full-shadow-playback/v1", "M49 playback schema");
+  exact(payload.result_id, id, "M49 playback result");
+  exact(payload.coordinate_frame, "map-gravity-local", "M49 playback frame");
+  exact(payload.access, "read-only", "M49 playback access");
+  const frameCount = exact(integer(payload.frame_count, "M49 playback frames"), 4489, "M49 playback frames");
+  const cellCount = exact(integer(payload.cell_count, "M49 playback cells"), 2244, "M49 playback cells");
+  const totalByteLength = integer(payload.total_byte_length, "M49 playback bytes");
+  if (!Array.isArray(payload.tracks) || payload.tracks.length !== 4) {
+    throw new M49TgsFullShadowContractError("M49 playback tracks: неверная размерность.");
+  }
+  const tracks = new Map<M49TgsFullShadowPlaybackTrackId, M49TgsFullShadowPlaybackTrack>();
+  for (const [index, value] of payload.tracks.entries()) {
+    const row = objectValue(value, `M49 playback track ${index}`);
+    const trackId = playbackTrackId(row.id, `M49 playback track ${index}.id`);
+    const sha256 = text(row.sha256, `M49 playback track ${trackId}.sha256`);
+    if (!/^[a-f0-9]{64}$/.test(sha256) || tracks.has(trackId)) {
+      throw new M49TgsFullShadowContractError(`M49 playback track ${trackId}: нарушена идентичность.`);
+    }
+    tracks.set(trackId, {
+      id: trackId,
+      url: text(row.url, `M49 playback track ${trackId}.url`),
+      mediaType: text(row.media_type, `M49 playback track ${trackId}.media_type`),
+      dtype: playbackDtype(row.dtype, `M49 playback track ${trackId}.dtype`),
+      shape: playbackShape(row.shape, `M49 playback track ${trackId}.shape`),
+      byteLength: integer(row.byte_length, `M49 playback track ${trackId}.byte_length`),
+      sha256,
+    });
+  }
+  if ([...tracks.values()].reduce((sum, track) => sum + track.byteLength, 0) !== totalByteLength) {
+    throw new M49TgsFullShadowContractError("M49 playback bytes: нарушен accounting.");
+  }
+  return { frameCount, cellCount, totalByteLength, tracks };
+}
+
+function sha256Hex(buffer: ArrayBuffer): Promise<string> {
+  if (!globalThis.crypto?.subtle) {
+    throw new M49TgsFullShadowContractError("Браузер не поддерживает проверку playback SHA-256.");
+  }
+  return globalThis.crypto.subtle.digest("SHA-256", buffer).then((digest) => (
+    [...new Uint8Array(digest)].map((value) => value.toString(16).padStart(2, "0")).join("")
+  ));
+}
+
+async function fetchPlaybackTrack(
+  track: M49TgsFullShadowPlaybackTrack,
+  fetcher: LaboratoryFetch,
+  signal: AbortSignal | undefined,
+  completedBytes: number,
+  totalBytes: number,
+  onProgress: ((progress: M49TgsFullShadowPlaybackProgress) => void) | undefined,
+): Promise<ArrayBuffer> {
+  const response = await fetcher(track.url, {
+    method: "GET",
+    headers: { Accept: track.mediaType },
+    signal,
+  });
+  if (!response.ok) {
+    throw new M49TgsFullShadowContractError(`M49 playback ${track.id} недоступен: HTTP ${response.status}.`);
+  }
+  const bytes = new Uint8Array(track.byteLength);
+  if (response.body) {
+    const reader = response.body.getReader();
+    let offset = 0;
+    while (true) {
+      const { done, value } = await reader.read();
+      if (done) break;
+      if (offset + value.byteLength > bytes.byteLength) {
+        throw new M49TgsFullShadowContractError(`M49 playback ${track.id}: превышен объявленный размер.`);
+      }
+      bytes.set(value, offset);
+      offset += value.byteLength;
+      onProgress?.({
+        phase: "download",
+        trackId: track.id,
+        loadedBytes: completedBytes + offset,
+        totalBytes,
+      });
+    }
+    if (offset !== bytes.byteLength) {
+      throw new M49TgsFullShadowContractError(`M49 playback ${track.id}: получен неполный файл.`);
+    }
+  } else {
+    const fallback = new Uint8Array(await response.arrayBuffer());
+    if (fallback.byteLength !== bytes.byteLength) {
+      throw new M49TgsFullShadowContractError(`M49 playback ${track.id}: получен неверный размер.`);
+    }
+    bytes.set(fallback);
+  }
+  onProgress?.({
+    phase: "verify",
+    trackId: track.id,
+    loadedBytes: completedBytes + bytes.byteLength,
+    totalBytes,
+  });
+  if (await sha256Hex(bytes.buffer) !== track.sha256) {
+    throw new M49TgsFullShadowContractError(`M49 playback ${track.id}: SHA-256 не совпал.`);
+  }
+  return bytes.buffer;
+}
+
+function equalShape(actual: readonly number[], expected: readonly number[]): boolean {
+  return actual.length === expected.length && actual.every((value, index) => value === expected[index]);
+}
+
+export function parseM49TgsNpyTrack(
+  buffer: ArrayBuffer,
+  expectedDtype: "<f4" | "|u1",
+  expectedShape: readonly number[],
+): Float32Array | Uint8Array {
+  const bytes = new Uint8Array(buffer);
+  if (bytes.byteLength < 12
+      || bytes[0] !== 0x93
+      || String.fromCharCode(...bytes.subarray(1, 6)) !== "NUMPY") {
+    throw new M49TgsFullShadowContractError("M49 playback NPY: неверная сигнатура.");
+  }
+  const major = bytes[6];
+  const headerLength = major === 1
+    ? new DataView(buffer).getUint16(8, true)
+    : major === 2 || major === 3
+      ? new DataView(buffer).getUint32(8, true)
+      : -1;
+  const headerOffset = major === 1 ? 10 : 12;
+  if (headerLength < 0 || headerOffset + headerLength > bytes.byteLength) {
+    throw new M49TgsFullShadowContractError("M49 playback NPY: неверный заголовок.");
+  }
+  const header = new TextDecoder("latin1").decode(bytes.subarray(headerOffset, headerOffset + headerLength));
+  const dtype = header.match(/["']descr["']\s*:\s*["']([^"']+)["']/)?.[1];
+  const fortran = header.match(/["']fortran_order["']\s*:\s*(True|False)/)?.[1];
+  const rawShape = header.match(/["']shape["']\s*:\s*\(([^)]*)\)/)?.[1];
+  const shape = rawShape?.split(",").map((value) => value.trim()).filter(Boolean).map(Number) ?? [];
+  if (dtype !== expectedDtype || fortran !== "False" || !equalShape(shape, expectedShape)) {
+    throw new M49TgsFullShadowContractError("M49 playback NPY: dtype или shape изменились.");
+  }
+  const count = expectedShape.reduce((product, value) => product * value, 1);
+  const dataOffset = headerOffset + headerLength;
+  const bytesPerValue = expectedDtype === "<f4" ? 4 : 1;
+  if (dataOffset + count * bytesPerValue !== buffer.byteLength) {
+    throw new M49TgsFullShadowContractError("M49 playback NPY: длина payload изменилась.");
+  }
+  return expectedDtype === "<f4"
+    ? new Float32Array(buffer, dataOffset, count)
+    : new Uint8Array(buffer, dataOffset, count);
+}
+
+function parsePlaybackFrames(buffer: ArrayBuffer): readonly M49TgsFullShadowPlaybackFrame[] {
+  const lines = new TextDecoder().decode(buffer).trim().split("\n");
+  if (lines.length !== 4489) {
+    throw new M49TgsFullShadowContractError("M49 playback frames: неверная размерность.");
+  }
+  return lines.map((line, sourceSequence) => {
+    const row = objectValue(JSON.parse(line), `M49 playback frame ${sourceSequence}`);
+    return {
+      sourceSequence,
+      sourceFrameIndex: integer(row.source_frame_index, `M49 playback frame ${sourceSequence}.source`),
+      sessionSeconds: numberValue(row.session_seconds, `M49 playback frame ${sourceSequence}.time`),
+      sampleAvailable: booleanValue(row.sample_available, `M49 playback frame ${sourceSequence}.available`),
+      metrics: {
+        eligiblePointCount: integer(row.eligible_point_count, `M49 playback frame ${sourceSequence}.eligible`),
+        groundPointCount: integer(row.ground_point_count, `M49 playback frame ${sourceSequence}.ground`),
+        nongroundPointCount: integer(row.nonground_point_count, `M49 playback frame ${sourceSequence}.nonground`),
+        rejectedPointCount: integer(row.rejected_point_count, `M49 playback frame ${sourceSequence}.rejected`),
+        occupiedCellCount: integer(row.occupied_cell_count, `M49 playback frame ${sourceSequence}.occupied`),
+      },
+    };
+  });
+}
+
+export async function fetchM49TgsFullShadowPlaybackPack(
+  id: string,
+  {
+    fetcher = fetch,
+    signal,
+    onProgress,
+  }: {
+    fetcher?: LaboratoryFetch;
+    signal?: AbortSignal;
+    onProgress?: (progress: M49TgsFullShadowPlaybackProgress) => void;
+  } = {},
+): Promise<M49TgsFullShadowPlaybackPack> {
+  if (!RESULT_ID.test(id)) {
+    throw new M49TgsFullShadowContractError("M49 playback identity недопустима.");
+  }
+  onProgress?.({ phase: "manifest", trackId: null, loadedBytes: 0, totalBytes: 0 });
+  const manifest = await fetchPlaybackManifest(id, fetcher, signal);
+  const buffers = new Map<M49TgsFullShadowPlaybackTrackId, ArrayBuffer>();
+  let completedBytes = 0;
+  const order: readonly M49TgsFullShadowPlaybackTrackId[] = ["frames", "centers", "states", "z-bounds"];
+  for (const trackId of order) {
+    const track = manifest.tracks.get(trackId);
+    if (!track) throw new M49TgsFullShadowContractError(`M49 playback ${trackId}: дорожка отсутствует.`);
+    const buffer = await fetchPlaybackTrack(
+      track,
+      fetcher,
+      signal,
+      completedBytes,
+      manifest.totalByteLength,
+      onProgress,
+    );
+    buffers.set(trackId, buffer);
+    completedBytes += track.byteLength;
+  }
+  const centersTrack = manifest.tracks.get("centers")!;
+  const statesTrack = manifest.tracks.get("states")!;
+  const zBoundsTrack = manifest.tracks.get("z-bounds")!;
+  const centersRaw = parseM49TgsNpyTrack(
+    buffers.get("centers")!,
+    "<f4",
+    centersTrack.shape,
+  ) as Float32Array;
+  const centersXyM = Array.from({ length: manifest.cellCount }, (_, index) => (
+    [centersRaw[index * 2]!, centersRaw[index * 2 + 1]!] as const
+  ));
+  const states = parseM49TgsNpyTrack(
+    buffers.get("states")!,
+    "|u1",
+    statesTrack.shape,
+  ) as Uint8Array;
+  const zBoundsM = parseM49TgsNpyTrack(
+    buffers.get("z-bounds")!,
+    "<f4",
+    zBoundsTrack.shape,
+  ) as Float32Array;
+  const frames = parsePlaybackFrames(buffers.get("frames")!);
+  onProgress?.({
+    phase: "ready",
+    trackId: null,
+    loadedBytes: manifest.totalByteLength,
+    totalBytes: manifest.totalByteLength,
+  });
+  return {
+    resultId: id,
+    frameCount: manifest.frameCount,
+    cellCount: manifest.cellCount,
+    totalByteLength: manifest.totalByteLength,
+    centersXyM,
+    states,
+    zBoundsM,
+    frames,
+  };
+}

apps/control-station/src/core/laboratory/m4ReplayThreat.ts

@@ -226,6 +226,20 @@ export interface M4ThreatTimelineChunk {
   frames: readonly M4ThreatTimelineFrame[];
 }
 
+export interface M4ThreatPlaybackProgress {
+  phase: "manifest" | "download" | "verify" | "ready";
+  loadedBytes: number;
+  totalBytes: number;
+}
+
+export interface M4ThreatPlaybackPointPack {
+  resultId: string;
+  frameCount: 4489;
+  pointCount: number;
+  pointOffsets: Uint32Array;
+  pointsMapXyzM: Float32Array;
+}
+
 type LaboratoryFetch = (input: RequestInfo | URL, init?: RequestInit) => Promise<Response>;
 export const M4_THREAT_TIMELINE_ENDPOINT_ROOT = "/api/v1/laboratory/m4-threat/results";
 class M4ThreatContractError extends Error {}
@@ -803,11 +817,13 @@ export async function fetchM4ThreatTimelineChunk(
     signal,
     endpointRoot = M4_THREAT_TIMELINE_ENDPOINT_ROOT,
     cameraObstacleProjectionDelivery = null,
+    playbackPointPack,
   }: {
     fetcher?: LaboratoryFetch;
     signal?: AbortSignal;
     endpointRoot?: string;
     cameraObstacleProjectionDelivery?: M4ThreatTimeline["cameraObstacleProjectionDelivery"];
+    playbackPointPack?: M4ThreatPlaybackPointPack;
   } = {},
 ): Promise<M4ThreatTimelineChunk> {
   const params = new URLSearchParams({
@@ -817,6 +833,7 @@ export async function fetchM4ThreatTimelineChunk(
   if (cameraObstacleProjectionDelivery !== null) {
     params.set("obstacle_projection", cameraObstacleProjectionDelivery);
   }
+  if (playbackPointPack) params.set("include_points", "false");
   const response = await fetcher(
     `${endpointRoot}/${result}/timeline/chunk?${params}`,
     { headers: { Accept: "application/json" }, signal },
@@ -834,8 +851,12 @@ export async function fetchM4ThreatTimelineChunk(
   if (parsedStart !== startSequence) {
     throw new M4ThreatContractError("M4.6 timeline chunk start: нарушен контракт.");
   }
-  const frames = array(payload.frames, "M4.6 timeline frames").map((raw, offset) =>
-    parseTimelineFrame(raw, result, parsedStart + offset, endpointRoot));
+  const frames = array(payload.frames, "M4.6 timeline frames").map((raw, offset) => {
+    const parsed = parseTimelineFrame(raw, result, parsedStart + offset, endpointRoot);
+    return playbackPointPack
+      ? hydrateM4ThreatTimelineFrame(parsed, playbackPointPack)
+      : parsed;
+  });
   const parsedCount = integer(payload.frame_count, "M4.6 timeline chunk count");
   if (parsedCount !== frames.length || parsedCount > frameCount) {
     throw new M4ThreatContractError("M4.6 timeline chunk count: нарушен контракт.");
@@ -851,6 +872,159 @@ export async function fetchM4ThreatTimelineChunk(
   };
 }
 
+function playbackSha256Hex(buffer: ArrayBuffer): Promise<string> {
+  if (!globalThis.crypto?.subtle) {
+    throw new M4ThreatContractError("Браузер не поддерживает проверку playback SHA-256.");
+  }
+  return globalThis.crypto.subtle.digest("SHA-256", buffer).then((digest) => (
+    [...new Uint8Array(digest)].map((value) => value.toString(16).padStart(2, "0")).join("")
+  ));
+}
+
+function roundedBodyCoordinate(value: number): number {
+  return Math.round(value * 1_000_000) / 1_000_000;
+}
+
+export function hydrateM4ThreatTimelineFrame(
+  frame: M4ThreatTimelineFrame,
+  pack: M4ThreatPlaybackPointPack,
+): M4ThreatTimelineFrame {
+  if (frame.sequence >= pack.frameCount || pack.resultId === "") {
+    throw new M4ThreatContractError("M4.6 binary playback frame: нарушена идентичность.");
+  }
+  if (!frame.sourceAvailable || !frame.spatialAvailable || !frame.bodyFrame) {
+    if (frame.pointCloudSourceCount !== 0) {
+      throw new M4ThreatContractError("M4.6 binary playback unavailable frame содержит точки.");
+    }
+    return { ...frame, pointCloudBodyXyzM: [], pointCloudSampleCount: 0 };
+  }
+  const start = pack.pointOffsets[frame.sequence];
+  const stop = pack.pointOffsets[frame.sequence + 1];
+  if (start === undefined || stop === undefined || stop < start || stop > pack.pointCount) {
+    throw new M4ThreatContractError("M4.6 binary playback offsets: нарушена размерность.");
+  }
+  const count = stop - start;
+  if (frame.pointCloudSourceCount !== count || frame.pointCloudSampleCount !== count) {
+    throw new M4ThreatContractError("M4.6 binary playback point accounting: нарушен контракт.");
+  }
+  const origin = frame.bodyFrame.originMapXyzM;
+  const basis = frame.bodyFrame.basisMapFromBody;
+  const points = new Array<M4Point3>(count);
+  for (let index = 0; index < count; index += 1) {
+    const sourceOffset = (start + index) * 3;
+    const dx = pack.pointsMapXyzM[sourceOffset]! - origin[0];
+    const dy = pack.pointsMapXyzM[sourceOffset + 1]! - origin[1];
+    const dz = pack.pointsMapXyzM[sourceOffset + 2]! - origin[2];
+    points[index] = [
+      roundedBodyCoordinate(dx * basis[0][0] + dy * basis[1][0] + dz * basis[2][0]),
+      roundedBodyCoordinate(dx * basis[0][1] + dy * basis[1][1] + dz * basis[2][1]),
+      roundedBodyCoordinate(dx * basis[0][2] + dy * basis[1][2] + dz * basis[2][2]),
+    ];
+  }
+  return { ...frame, pointCloudBodyXyzM: points, pointCloudSampleCount: count };
+}
+
+export async function fetchM4ThreatPlaybackPointPack(
+  result: string,
+  {
+    fetcher = fetch,
+    signal,
+    endpointRoot = M4_THREAT_TIMELINE_ENDPOINT_ROOT,
+    onProgress,
+  }: {
+    fetcher?: LaboratoryFetch;
+    signal?: AbortSignal;
+    endpointRoot?: string;
+    onProgress?: (progress: M4ThreatPlaybackProgress) => void;
+  } = {},
+): Promise<M4ThreatPlaybackPointPack> {
+  resultId(result);
+  onProgress?.({ phase: "manifest", loadedBytes: 0, totalBytes: 0 });
+  const manifestResponse = await fetcher(`${endpointRoot}/${result}/timeline/playback`, {
+    headers: { Accept: "application/json" },
+    signal,
+  });
+  if (!manifestResponse.ok) {
+    throw new M4ThreatContractError(`M4.6 playback manifest: HTTP ${manifestResponse.status}.`);
+  }
+  const manifest = object(await manifestResponse.json(), "M4.6 playback manifest");
+  exact(manifest.schema_version, "missioncore.recorded-spatial-playback/v1", "M4.6 playback schema");
+  exact(manifest.result_id, result, "M4.6 playback result");
+  exact(manifest.coordinate_frame, "map", "M4.6 playback coordinate frame");
+  exact(manifest.access, "read-only-sealed-binary-playback", "M4.6 playback access");
+  const frameCount = exact(integer(manifest.frame_count, "M4.6 playback frames"), 4489, "M4.6 playback frames");
+  const pointCount = integer(manifest.point_count, "M4.6 playback points");
+  const offsetsRaw = array(manifest.point_offsets, "M4.6 playback offsets");
+  if (offsetsRaw.length !== frameCount + 1) {
+    throw new M4ThreatContractError("M4.6 playback offsets: неверная размерность.");
+  }
+  const pointOffsets = Uint32Array.from(offsetsRaw, (value) => integer(value, "M4.6 playback offset"));
+  if (pointOffsets[0] !== 0 || pointOffsets[pointOffsets.length - 1] !== pointCount) {
+    throw new M4ThreatContractError("M4.6 playback offsets: нарушено замыкание.");
+  }
+  for (let index = 1; index < pointOffsets.length; index += 1) {
+    if (pointOffsets[index]! < pointOffsets[index - 1]!) {
+      throw new M4ThreatContractError("M4.6 playback offsets: нарушена монотонность.");
+    }
+  }
+  const track = object(manifest.track, "M4.6 playback track");
+  exact(track.id, "points-map-f32", "M4.6 playback track id");
+  exact(track.dtype, "<f4", "M4.6 playback dtype");
+  const shape = array(track.shape, "M4.6 playback shape").map((value) => integer(value, "M4.6 playback shape"));
+  if (shape.length !== 2 || shape[0] !== pointCount || shape[1] !== 3) {
+    throw new M4ThreatContractError("M4.6 playback shape: нарушена размерность.");
+  }
+  const byteLength = integer(track.bytes, "M4.6 playback bytes");
+  if (byteLength !== pointCount * 3 * Float32Array.BYTES_PER_ELEMENT) {
+    throw new M4ThreatContractError("M4.6 playback bytes: нарушен accounting.");
+  }
+  const sha256 = text(track.sha256, "M4.6 playback SHA-256");
+  if (!/^[a-f0-9]{64}$/.test(sha256)) {
+    throw new M4ThreatContractError("M4.6 playback SHA-256: нарушен контракт.");
+  }
+  const response = await fetcher(text(track.url, "M4.6 playback URL"), {
+    headers: { Accept: "application/octet-stream" },
+    signal,
+  });
+  if (!response.ok) throw new M4ThreatContractError(`M4.6 playback points: HTTP ${response.status}.`);
+  const bytes = new Uint8Array(byteLength);
+  if (response.body) {
+    const reader = response.body.getReader();
+    let offset = 0;
+    while (true) {
+      const { done, value } = await reader.read();
+      if (done) break;
+      if (offset + value.byteLength > bytes.byteLength) {
+        throw new M4ThreatContractError("M4.6 playback points превысил объявленный размер.");
+      }
+      bytes.set(value, offset);
+      offset += value.byteLength;
+      onProgress?.({ phase: "download", loadedBytes: offset, totalBytes: byteLength });
+    }
+    if (offset !== byteLength) {
+      throw new M4ThreatContractError("M4.6 playback points получен не полностью.");
+    }
+  } else {
+    const fallback = new Uint8Array(await response.arrayBuffer());
+    if (fallback.byteLength !== byteLength) {
+      throw new M4ThreatContractError("M4.6 playback points: неверный размер.");
+    }
+    bytes.set(fallback);
+  }
+  onProgress?.({ phase: "verify", loadedBytes: byteLength, totalBytes: byteLength });
+  if (await playbackSha256Hex(bytes.buffer) !== sha256) {
+    throw new M4ThreatContractError("M4.6 playback points: SHA-256 не совпал.");
+  }
+  onProgress?.({ phase: "ready", loadedBytes: byteLength, totalBytes: byteLength });
+  return {
+    resultId: result,
+    frameCount,
+    pointCount,
+    pointOffsets,
+    pointsMapXyzM: new Float32Array(bytes.buffer),
+  };
+}
+
 export async function fetchM4ThreatCameraPointOverlay(
   result: string,
   sequence: number,