Merge latest main into S2 GhostMaps contribution

src/data/cctvMediaFeedType.test.mjs

@@ -33,6 +33,14 @@ const VIDEO = {
   feedType: 'video',
   url: 'https://cams.upstream.invalid/live.mp4',
 };
+const WEBM = {
+  id: 'webm-fixture',
+  name: 'WebM fixture',
+  lat: 30.27,
+  lon: -97.74,
+  feedType: 'webm',
+  url: 'https://cams.upstream.invalid/live.webm',
+};
 const MJPEG = {
   id: 'mjpeg-fixture',
   name: 'MJPEG fixture',
@@ -69,7 +77,10 @@ function recordingResponse() {
     body: '',
     writeHead(status, headers) {
       res.statusCode = status;
-      res.headers = headers || {};
+      res.headers = { ...res.headers, ...headers };
+    },
+    setHeader(name, value) {
+      res.headers[name] = value;
     },
     write(chunk) {
       chunks.push(Buffer.from(chunk));
@@ -105,6 +116,7 @@ function mount(t, respond) {
     STILL,
     STILL_ALIAS,
     VIDEO,
+    WEBM,
     MJPEG,
   ]);
   process.env.CCTV_SOURCES_FILE = 'absent-source-file.json';
@@ -143,9 +155,9 @@ function mount(t, respond) {
   });
   assert.ok(handler, 'the CCTV provider must mount a middleware');
 
-  const call = async (path) => {
+  const call = async (path, headers = {}) => {
     const { res, done } = recordingResponse();
-    await handler({ url: path, headers: {}, method: 'GET', on() {} }, res);
+    await handler({ url: path, headers, method: 'GET', on() {} }, res);
     await done;
     return res;
   };
@@ -268,3 +280,251 @@ test('/frame does not follow a still camera off its origin', async (t) => {
     [STILL.url],
   );
 });
+
+/** An upstream Response whose body records whether it was cancelled. */
+function trackedUpstream({ status = 200, headers = {}, body = 'payload' }) {
+  const state = { cancelled: false };
+  const response = new Response(
+    new ReadableStream(
+      {
+        pull(controller) {
+          controller.enqueue(new TextEncoder().encode(body));
+          controller.close();
+        },
+        cancel() {
+          state.cancelled = true;
+        },
+      },
+      { highWaterMark: 0 },
+    ),
+    { status, headers },
+  );
+  return { response, state };
+}
+
+test('/media refuses an upstream type that does not match the feed kind', async (t) => {
+  let current;
+  const app = mount(t, () => current.response);
+  for (const [camera, contentType, body] of [
+    [VIDEO, 'text/html', '<!doctype html><p>x</p>'],
+    [VIDEO, 'image/svg+xml', '<svg xmlns="http://www.w3.org/2000/svg"/>'],
+    [VIDEO, 'application/vnd.apple.mpegurl', '#EXTM3U'],
+    [VIDEO, 'video/webm', 'video'],
+    [VIDEO, undefined, 'video'],
+    [WEBM, 'video/mp4', 'video'],
+    [MJPEG, 'multipart/x-mixed-replace', '--frame'],
+    [MJPEG, 'multipart/x-mixed-replace; boundary=', '--frame'],
+    [MJPEG, 'image/jpeg', 'jpeg'],
+    [MJPEG, 'text/html; boundary=frame', '<!doctype html><p>x</p>'],
+  ]) {
+    current = trackedUpstream({
+      headers: contentType === undefined ? {} : { 'content-type': contentType },
+      body,
+    });
+    const label = `${camera.id}: ${contentType}`;
+    const res = await app.call(`/media/${camera.id}`);
+    assert.equal(res.statusCode, 502, label);
+    assert.equal(res.headers['Content-Type'], 'application/json', label);
+    assert.deepEqual(JSON.parse(res.body), { error: 'Media proxy failed' });
+    assert.equal(current.state.cancelled, true, `${label}: upstream cancelled`);
+    const health = await app.health(camera.id);
+    assert.equal(health.status, 'degraded', label);
+    assert.equal(health.message, 'Unexpected media type', label);
+  }
+});
+
+test('/media relays each feed kind under its canonical type, including a partial response', async (t) => {
+  let current;
+  const app = mount(t, () => current);
+  for (const [camera, upstream, expected] of [
+    [VIDEO, { 'content-type': 'Video/MP4; codecs="avc1.42E01E"' }, 'video/mp4'],
+    [
+      VIDEO,
+      {
+        'content-type': 'video/mp4',
+        'content-range': 'bytes 0-4/100',
+        'content-length': '5',
+        'accept-ranges': 'bytes',
+      },
+      'video/mp4',
+    ],
+    [WEBM, { 'content-type': 'video/webm' }, 'video/webm'],
+    [
+      MJPEG,
+      { 'content-type': 'multipart/x-mixed-replace;boundary="frame"' },
+      'multipart/x-mixed-replace; boundary=frame',
+    ],
+    [
+      MJPEG,
+      { 'content-type': 'multipart/x-mixed-replace; boundary="a b"' },
+      'multipart/x-mixed-replace; boundary="a b"',
+    ],
+  ]) {
+    const status = upstream['content-range'] ? 206 : 200;
+    current = upstreamResponse({ status, headers: upstream, body: 'bytes' });
+    const res = await app.call(`/media/${camera.id}`);
+    assert.equal(res.statusCode, status, camera.id);
+    assert.equal(res.headers['Content-Type'], expected);
+    assert.equal(res.body, 'bytes');
+    if (status === 206)
+      assert.equal(res.headers['Content-Range'], 'bytes 0-4/100');
+    assert.equal((await app.health(camera.id)).status, 'ok');
+  }
+});
+
+test('/media does not follow a live camera off its origin', async (t) => {
+  const app = mount(t, ({ url }) =>
+    url === VIDEO.url
+      ? upstreamResponse({
+          status: 302,
+          headers: { location: 'https://elsewhere.invalid/live.mp4' },
+          body: '',
+        })
+      : upstreamResponse({
+          headers: { 'content-type': 'video/mp4' },
+          body: 'elsewhere',
+        }),
+  );
+  const res = await app.call(`/media/${VIDEO.id}`);
+  assert.equal(res.statusCode, 502);
+  assert.doesNotMatch(res.body, /elsewhere/);
+  assert.deepEqual(app.requests, [{ url: VIDEO.url, redirect: 'manual' }]);
+});
+
+test('every CCTV route refuses cross-site requests and admits the app itself', async (t) => {
+  const app = mount(t, ({ url }) =>
+    upstreamResponse({
+      headers: {
+        'content-type': url === VIDEO.url ? 'video/mp4' : 'image/jpeg',
+      },
+      body: 'bytes',
+    }),
+  );
+  const host = 'localhost:5173';
+  const paths = [
+    '/sources',
+    '/health',
+    `/stream/${STILL.id}`,
+    `/frame/${STILL.id}`,
+    `/media/${VIDEO.id}`,
+  ];
+  for (const headers of [
+    { host, 'sec-fetch-site': 'cross-site' },
+    { host, 'sec-fetch-site': 'same-site' },
+    { host, origin: 'https://elsewhere.example' },
+    { host, origin: 'null' },
+  ])
+    for (const path of paths) {
+      const res = await app.call(path, headers);
+      assert.equal(res.statusCode, 403, `${path} ${JSON.stringify(headers)}`);
+    }
+  assert.deepEqual(app.requests, [], 'a refused request reached an upstream');
+  for (const headers of [
+    { host, 'sec-fetch-site': 'same-origin' },
+    { host, origin: `http://${host}` },
+    {},
+  ]) {
+    const frame = await app.call(`/frame/${STILL.id}`, headers);
+    assert.equal(frame.statusCode, 200);
+    assert.equal(frame.headers['X-CCTV-Source'], 'upstream-image');
+    const media = await app.call(`/media/${VIDEO.id}`, headers);
+    assert.equal(media.statusCode, 200);
+    assert.equal(media.headers['Content-Type'], 'video/mp4');
+  }
+});
+
+test('/frame falls back past a non-raster upstream and Street View frame', async (t) => {
+  let streetViewType;
+  const app = mount(t, ({ url }) =>
+    url.startsWith('https://maps.googleapis.com/')
+      ? trackedUpstream({
+          headers:
+            streetViewType === undefined
+              ? {}
+              : { 'content-type': streetViewType },
+          body: 'street-view',
+        }).response
+      : upstreamResponse({
+          headers: { 'content-type': 'image/svg+xml' },
+          body: '<svg xmlns="http://www.w3.org/2000/svg"/>',
+        }),
+  );
+  process.env.GOOGLE_MAPS_SERVER_API_KEY = 'fixture-key';
+  for (const type of [
+    'image/svg+xml',
+    'text/html',
+    'application/xml',
+    undefined,
+  ]) {
+    streetViewType = type;
+    const res = await app.call(`/frame/${STILL.id}`);
+    assert.equal(res.statusCode, 200);
+    assert.equal(res.headers['X-CCTV-Source'], 'synthetic', String(type));
+    assert.doesNotMatch(res.body, /street-view/);
+  }
+  streetViewType = 'image/JPEG; charset=x';
+  const res = await app.call(`/frame/${STILL.id}`);
+  assert.equal(res.headers['X-CCTV-Source'], 'streetview');
+  assert.equal(res.headers['Content-Type'], 'image/jpeg');
+  assert.equal(res.body, 'street-view');
+});
+
+test('a forwarded same-origin request reaches every CCTV route but not the Street View fallback', async (t) => {
+  const app = mount(t, ({ url }) => {
+    if (url.startsWith('https://maps.googleapis.com/'))
+      return trackedUpstream({
+        headers: { 'content-type': 'image/jpeg' },
+        body: 'street-view',
+      }).response;
+    return url === VIDEO.url
+      ? upstreamResponse({ headers: { 'content-type': 'video/mp4' } })
+      : upstreamResponse({ status: 503, body: '' });
+  });
+  process.env.GOOGLE_MAPS_SERVER_API_KEY = 'fixture-key';
+  const host = 'localhost:5173';
+  const streetViewCalls = () =>
+    app.requests.filter(({ url }) =>
+      url.startsWith('https://maps.googleapis.com/'),
+    ).length;
+  for (const forwarded of [
+    { 'x-forwarded-for': '203.0.113.9' },
+    { via: '1.1 proxy' },
+    { forwarded: 'for=203.0.113.9' },
+    { 'x-real-ip': '203.0.113.9' },
+    { 'x-forwarded-for': '' },
+    { 'x-forwarded-for': '  ' },
+    { 'cf-connecting-ip': '' },
+  ]) {
+    const headers = { host, 'sec-fetch-site': 'same-origin', ...forwarded };
+    const label = JSON.stringify(forwarded);
+    assert.equal((await app.call('/sources', headers)).statusCode, 200, label);
+    const media = await app.call(`/media/${VIDEO.id}`, headers);
+    assert.equal(media.statusCode, 200, label);
+    assert.equal(media.headers['Content-Type'], 'video/mp4', label);
+    const frame = await app.call(`/frame/${STILL.id}`, headers);
+    assert.equal(frame.statusCode, 200, label);
+    assert.equal(frame.headers['X-CCTV-Source'], 'synthetic', label);
+    assert.equal(frame.headers['Content-Type'], 'image/svg+xml', label);
+    // Cross-site stays refused whatever the forwarding headers say.
+    for (const path of ['/sources', `/frame/${STILL.id}`, `/media/${VIDEO.id}`])
+      assert.equal(
+        (
+          await app.call(path, {
+            ...forwarded,
+            host,
+            'sec-fetch-site': 'cross-site',
+          })
+        ).statusCode,
+        403,
+        `${label} ${path}`,
+      );
+  }
+  assert.equal(streetViewCalls(), 0, 'a forwarded request spent the key');
+  const direct = await app.call(`/frame/${STILL.id}`, {
+    host,
+    'sec-fetch-site': 'same-origin',
+  });
+  assert.equal(direct.headers['X-CCTV-Source'], 'streetview');
+  assert.equal(direct.body, 'street-view');
+  assert.equal(streetViewCalls(), 1);
+});

src/data/cctvProxy.test.mjs

@@ -259,3 +259,57 @@ test('rejected snapshot responses abort the upstream download', async () => {
     assert.equal(signal.aborted, true);
   }
 });
+
+test('CCTV upstream frame fetch accepts only raster image types and sends their canonical type', async () => {
+  const frame = (contentType, body = 'frame') => {
+    const state = { cancelled: false };
+    const headers = contentType === null ? {} : { 'Content-Type': contentType };
+    const response = new Response(new ReadableStream({
+      pull(controller) {
+        controller.enqueue(new TextEncoder().encode(body));
+        controller.close();
+      },
+      cancel() {
+        state.cancelled = true;
+      },
+    }, { highWaterMark: 0 }), { status: 200, headers });
+    return { response, state };
+  };
+  for (const [contentType, canonical] of [
+    ['image/jpeg', 'image/jpeg'],
+    ['image/JPEG; charset=x', 'image/jpeg'],
+    [' Image/PNG ', 'image/png'],
+    ['image/gif', 'image/gif'],
+    ['image/webp;q=1', 'image/webp'],
+    ['image/avif', 'image/avif'],
+  ]) {
+    const { response } = frame(contentType);
+    const result = await fetchCctvImageFromUpstream('https://example.com/frame.jpg', {
+      fetchImpl: async () => response,
+    });
+    assert.equal(result?.contentType, canonical, contentType);
+    assert.equal(result.body.toString(), 'frame');
+  }
+  for (const [contentType, body] of [
+    ['image/svg+xml', '<svg xmlns="http://www.w3.org/2000/svg"/>'],
+    ['Image/SVG+XML; charset=utf-8', '<svg xmlns="http://www.w3.org/2000/svg"/>'],
+    ['text/html', '<!doctype html><p>x</p>'],
+    ['text/html; charset=utf-8', '<!doctype html><p>x</p>'],
+    ['application/xml', '<x/>'],
+    ['text/xml', '<x/>'],
+    [null, 'frame'],
+    ['', 'frame'],
+    ['image', 'frame'],
+    ['image/', 'frame'],
+    ['image/jpeg/x', 'frame'],
+    ['image/jpeg, text/html', 'frame'],
+    ['application/octet-stream', 'frame'],
+  ]) {
+    const { response, state } = frame(contentType, body);
+    const result = await fetchCctvImageFromUpstream('https://example.com/frame.jpg', {
+      fetchImpl: async () => response,
+    });
+    assert.equal(result, null, String(contentType));
+    assert.equal(state.cancelled, true, `${contentType}: body cancelled`);
+  }
+});

src/data/cctvSourcePins.test.mjs

@@ -0,0 +1,114 @@
+// Camera catalogs are pinned to their agency's image directory. The pin is a
+// parsed-URL check, not a string prefix, so a path that only starts with the
+// directory before dot segments, an encoded separator, credentials or another
+// port are resolved never counts as inside it, and a redirect on a pinned host
+// cannot leave the directory either.
+//
+// Run with: npm test   (node --test)
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { loadTflSourcesFromOpenData } from '../../server/providers/cctv/sources.js';
+import { fetchWithinHost } from '../../server/providers/cctv/media.js';
+import { pinnedCameraUrl } from '../../server/providers/cctv/normalize.js';
+
+const BUCKET = 'https://s3-eu-west-1.amazonaws.com/jamcams.tfl.gov.uk/';
+
+/** One available JamCam whose frame is at `imageUrl`. */
+const jamCam = (n, imageUrl) => ({
+  id: `JamCams_00001.0000${n}`,
+  commonName: `JamCam ${n}`,
+  lat: 51.5072,
+  lon: -0.1276,
+  additionalProperties: [
+    { key: 'available', value: 'true' },
+    { key: 'imageUrl', value: imageUrl },
+  ],
+});
+
+test('TfL JamCams keep only frames inside the official bucket, by parsed URL', async (t) => {
+  t.mock.method(console, 'log', () => {});
+  t.mock.method(console, 'warn', () => {});
+  const accepted = [
+    [`${BUCKET}00001.00001.jpg`, `${BUCKET}00001.00001.jpg`],
+    [`${BUCKET}00001.00002.jpg?t=1`, `${BUCKET}00001.00002.jpg?t=1`],
+    [
+      'https://s3-eu-west-1.amazonaws.com:443/jamcams.tfl.gov.uk/00001.00003.jpg',
+      `${BUCKET}00001.00003.jpg`,
+    ],
+  ];
+  const rejected = [
+    `${BUCKET}../other/x.jpg`,
+    `${BUCKET}%2e%2e/other/x.jpg`,
+    `${BUCKET}%2E%2E/other/x.jpg`,
+    `${BUCKET}.%2e/other/x.jpg`,
+    `${BUCKET}..%2fother/x.jpg`,
+    `${BUCKET}..%5Cother/x.jpg`,
+    `${BUCKET}..\\other\\x.jpg`,
+    'https://s3-eu-west-1.amazonaws.com/jamcams.tfl.gov.uk.other/x.jpg',
+    'https://s3-eu-west-1.amazonaws.com/jamcams.tfl.gov.uk-other/x.jpg',
+    'https://s3-eu-west-1.amazonaws.com/other/jamcams.tfl.gov.uk/x.jpg',
+    'https://user:[email protected]/jamcams.tfl.gov.uk/x.jpg',
+    'https://s3-eu-west-1.amazonaws.com:8443/jamcams.tfl.gov.uk/x.jpg',
+    'http://s3-eu-west-1.amazonaws.com/jamcams.tfl.gov.uk/x.jpg',
+    'https://s3-eu-west-1.amazonaws.com.other.example/jamcams.tfl.gov.uk/x.jpg',
+    'not a url',
+  ];
+  t.mock.method(globalThis, 'fetch', async () =>
+    Response.json(
+      [...accepted.map(([url]) => url), ...rejected].map((url, i) =>
+        jamCam(i + 1, url),
+      ),
+    ),
+  );
+  const cameras = await loadTflSourcesFromOpenData();
+  assert.deepEqual(
+    cameras.map((camera) => camera.url),
+    accepted.map(([, normalized]) => normalized),
+  );
+});
+
+test('a redirect on a pinned camera host stays inside the pinned directory', async () => {
+  const redirectTo = (location) => async (url) =>
+    url === `${BUCKET}00001.00001.jpg`
+      ? new Response(null, { status: 302, headers: { location } })
+      : new Response('frame', { headers: { 'content-type': 'image/jpeg' } });
+  for (const location of [
+    '/jamcams.tfl.gov.uk.other/x.jpg',
+    '/other/x.jpg',
+    '/jamcams.tfl.gov.uk/../other/x.jpg',
+    '/jamcams.tfl.gov.uk/%2e%2e/other/x.jpg',
+    '/jamcams.tfl.gov.uk/..%2fother/x.jpg',
+  ])
+    assert.equal(
+      await fetchWithinHost(
+        `${BUCKET}00001.00001.jpg`,
+        {},
+        redirectTo(location),
+      ),
+      null,
+      location,
+    );
+  const followed = await fetchWithinHost(
+    `${BUCKET}00001.00001.jpg`,
+    {},
+    redirectTo('/jamcams.tfl.gov.uk/00001.00002.jpg'),
+  );
+  assert.equal(await followed.text(), 'frame');
+  // A host with no pinned directory keeps the same-origin rule alone.
+  const unpinned = await fetchWithinHost(
+    'https://cams.example/a/frame.jpg',
+    {},
+    async (url) =>
+      url === 'https://cams.example/a/frame.jpg'
+        ? new Response(null, { status: 302, headers: { location: '/b/x.jpg' } })
+        : new Response('frame'),
+  );
+  assert.equal(await unpinned.text(), 'frame');
+});
+
+test('a pin prefix without a trailing slash still names a directory', () => {
+  assert.equal(
+    pinnedCameraUrl('https://h.example/camsX/a.jpg', 'https://h.example/cams'),
+    null,
+  );
+});

src/data/dataCredits.js

@@ -429,6 +429,13 @@ export const DATA_CREDITS = [
       'ECMWF does not accept any liability whatsoever for any error or omission in the data, their availability, or for any loss or damage arising from their use.',
   },
   // ── Bundled snapshots ───────────────────────────────────────────
+  {
+    key: 'sky-background',
+    html:
+      'Stars: <a href="https://cdsarc.cds.unistra.fr/viz-bin/cat/V/50" target="_blank" rel="noopener">Yale Bright Star Catalogue</a> ' +
+      '(Hoffleit &amp; Warren, via CDS). Milky Way: <a href="https://www.eso.org/public/images/eso0932a/" target="_blank" rel="noopener">ESO/S. Brunier</a> ' +
+      '(<a href="https://creativecommons.org/licenses/by/4.0/" target="_blank" rel="noopener">CC BY 4.0</a>; stars removed, blurred and reprojected)',
+  },
   {
     key: 'dams',
     html: 'Dams: Open Infrastructure Map',

src/data/gbfsProxy.test.mjs

@@ -304,3 +304,61 @@ test('GBFS rejects redirects and caps bodies through both server hooks', async (
     globalThis.fetch = originalFetch;
   }
 });
+
+test('GBFS relays only JSON, re-serialized under a fixed type, through both server hooks', async () => {
+  const { gbfsProxy } = await import('../../server/providers/gbfs.js');
+  const originalFetch = globalThis.fetch;
+  try {
+    for (const hook of ['configureServer', 'configurePreviewServer']) {
+      let handler;
+      gbfsProxy()[hook]({
+        middlewares: {
+          use(_path, callback) {
+            handler = callback;
+          },
+        },
+      });
+      const request = async (response) => {
+        globalThis.fetch = async () => response;
+        const res = {};
+        await handler(
+          { method: 'GET', url: '/' + encodeURIComponent(STATION_URL) },
+          {
+            writeHead(code, headers) {
+              Object.assign(res, { status: code, headers });
+            },
+            end(value) {
+              res.body = value;
+            },
+          },
+        );
+        return res;
+      };
+      for (const [contentType, body] of [
+        ['text/html', '<!doctype html><p>x</p>'],
+        ['application/json', '<!doctype html><p>x</p>'],
+        ['image/svg+xml', '<svg xmlns="http://www.w3.org/2000/svg"/>'],
+        ['application/json', ''],
+      ]) {
+        const res = await request(
+          new Response(body, { headers: { 'Content-Type': contentType } }),
+        );
+        assert.equal(res.status, 502, `${hook}: ${contentType} ${body}`);
+        assert.equal(res.headers['Content-Type'], 'application/json');
+        assert.equal(typeof JSON.parse(res.body).error, 'string');
+        assert.doesNotMatch(res.body, /doctype|svg/);
+      }
+      const res = await request(
+        new Response(' { "data" : { "stations" : [] } } ', {
+          headers: { 'Content-Type': 'text/html; charset=iso-8859-1' },
+        }),
+      );
+      assert.equal(res.status, 200);
+      assert.equal(res.headers['Content-Type'], 'application/json; charset=utf-8');
+      assert.equal(res.headers['Cache-Control'], 'no-store');
+      assert.equal(res.body, STATION_BODY);
+    }
+  } finally {
+    globalThis.fetch = originalFetch;
+  }
+});

src/data/local_data/sky/README.md

@@ -0,0 +1,51 @@
+# Sky background
+
+Catalogue stars over a soft Milky Way, drawn by `src/sky/starrySky.js` in
+place of Cesium's blocky Tycho-2 sky box.
+
+| File | Content | Size |
+| ---- | ------- | ---- |
+| `bright_stars.json` | 9,096 stars: J2000 RA/Dec, V magnitude, B−V | 235 KB |
+| `milkyway_{px,nx,py,ny,pz,nz}.webp` | Milky Way glow, six 1024² cube faces, no stars | 62 KB |
+
+## Stars — Yale Bright Star Catalogue
+
+**Source:** 5th Revised Edition (Hoffleit & Warren 1991), CDS catalogue
+[V/50](https://cdsarc.cds.unistra.fr/viz-bin/cat/V/50), file
+`https://cdsarc.cds.unistra.fr/ftp/V/50/catalog.gz` (sha256
+`3dc44b1e90be8fbe5bcc7656032560f51275f985c7e3f783c9028e1838ec7bed`, fetched
+2026-10-19).
+
+**License:** public domain. CDS asks for an acknowledgement; the "Data
+attribution" popover carries it.
+
+**Build:** `node scripts/build-bright-stars.mjs [catalog.gz]`. Drops the 14
+records without a J2000 position; rounds RA/Dec to 0.001° and magnitudes to
+0.01.
+
+## Milky Way — ESO/S. Brunier
+
+**Source:** ESO image [eso0932a](https://www.eso.org/public/images/eso0932a/),
+`https://cdn.eso.org/images/original/eso0932a.tif` (6000×3000 sRGB TIFF, sha256
+`10f209ab83e1fd89e7fa1ed70277ffc6ed19c43549f04ec637c6806d98aff035`, fetched
+2026-10-19).
+
+**License:** [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/).
+**Credit: ESO/S. Brunier.**
+
+**Changes made** (CC BY 4.0 asks for them): resampled to 4096×2048; stars
+removed; two images of Jupiter painted over; blurred (0.4°, 2° in the faint
+glow); reprojected to ICRF cube faces; black level at the median sky; saved as
+WebP. Build: `node scripts/build-milky-way.mjs <eso0932a.tif>`.
+
+The panorama's stars sit up to ~2° off; that is invisible in the blurred glow,
+and every sharp star comes from the catalogue.
+
+NASA SVS "Deep Star Maps 2020" was not used: it derives from Gaia DR2, which
+ESA licenses CC BY-NC 3.0 IGO.
+
+## Frame
+
+Both layers are in ICRF/J2000. The cube faces use the WebGL face layout, +X
+to the March equinox and +Z to the north celestial pole, uploaded without
+`flipY`.