fix(satellites): a SATCAT failure no longer stops TLE refreshes

Both CelesTrak routes shared one cooldown, and any failure set it: one bad
SATCAT answer made /api/celestrak return 502 "cooling down" for a minute,
failing the Starlink load and stalling every TLE group past its cache.
Throttling (403/429) still holds both routes off, since CelesTrak throttles
the client; any other failure holds off only the route that failed.

src/tooling/spaceProviders.test.mjs

@@ -359,6 +359,40 @@ test('SATCAT is proxied per core group for a day, separately from TLEs, and serv
   assert.equal(stale.headers['x-satcat-cache'], 'STALE-ERROR');
 });
 
+test('a SATCAT failure never holds off the TLEs, but CelesTrak throttling holds off both', async (t) => {
+  isolateDisk(t);
+  t.mock.method(console, 'warn', () => {});
+  const tle =
+    'ISS (ZARYA)\n1 25544U 98067A   24001.00000000  .00016717  00000-0  10270-3 0  9001\n2 25544  51.6416 247.4627 0006703 130.5360 325.0288 15.50000000    04\n';
+  let satcatAnswer = () => new Response('<html>not csv</html>');
+  const fetched = [];
+  t.mock.method(globalThis, 'fetch', async (url) => {
+    const parsed = new URL(url);
+    fetched.push(parsed.pathname);
+    return parsed.pathname.startsWith('/satcat/')
+      ? satcatAnswer()
+      : new Response(tle);
+  });
+  const request = install(celestrakProxy());
+  assert.equal((await request('/api/celestrak-satcat', '/sar')).status, 502);
+  const starlink = await request('/api/celestrak', '/starlink');
+  assert.equal(starlink.status, 200, 'the TLE feed is not cooling down');
+  assert.equal(starlink.body, tle);
+
+  // A 429 is CelesTrak throttling this client: every feed waits it out.
+  satcatAnswer = () =>
+    new Response('slow down', {
+      status: 429,
+      headers: { 'Retry-After': '120' },
+    });
+  const throttled = install(celestrakProxy());
+  await throttled('/api/celestrak-satcat', '/visual');
+  const before = fetched.length;
+  const held = await throttled('/api/celestrak', '/geo');
+  assert.equal(held.status, 502);
+  assert.equal(fetched.length, before, 'nothing went upstream');
+});
+
 test('CelesTrak admits a same-origin request behind the documented reverse proxy and refuses foreign origins', async (t) => {
   isolateDisk(t);
   let calls = 0;