Move satellites, launches and the sky with the world time

Layers whose data has a time of its own follow the page's world clock from
the start; live feeds such as flights, military, vessels and transit stay
live. Launches register the span of the launches loaded, so turning them on
brings up the timeline. Each timed layer registers its coverage once and
reports none while off, telling the clock after each step has settled. The
launch feed keeps its own window, and an orbit ring is drawn again once the
world time has moved far from when it was drawn.

src/voice/analystAccessors.test.mjs

@@ -74,9 +74,11 @@ test('bikeshare stations join coordinates from station information', () => {
   assert.deepEqual(methods.getAnalystRecords(), []);
 });
 
-test('launches carry time and hours until launch', () => {
-  const at = Date.now() + 5 * 3_600_000;
+test('launches carry time and hours until launch at the world time', () => {
+  const now = Date.UTC(2026, 10, 1);
+  const at = now + 5 * 3_600_000;
   const state = {
+    now: () => now,
     _enabled: true,
     _launches: [
       {