Fixed world clock: no player time controls (ISS-117)

The world always runs at WORLD_TIME_SCALE = 24 (lib/worldClock.ts). A server
background tick (instrumentation.ts -> startBackgroundTick, 1 s interval)
advances the sim with no open browser; idle-pause freezes the clock exactly
while no plane is flying or in repair. Fresh worlds start year 2000
(STARTING_CLOCK_MS in seed.ts).

- Removed: POST /api/sim + OpenAPI entry, applyTimeControls/clampTimeScale,
  lib/timeScale.ts, LeftPane pause button + scale slider machinery,
  ISS-057 slow-on-landing/resume in flyPlane.
- Snapshot simState is now { clockMs } only; client extrapolates at the fixed
  rate between polls and freezes while idle (useSimClock).
- New test-only hook POST /api/test/set-timescale behind FLIGHT_TEST_HOOKS=1
  (sibling of set-health); all e2e setScale helpers call it, afterEach restores
  the world rate. E2E pause tests replaced by idle-pause assertions; sim.spec.ts
  activates the world via set-health + /repair for advance/expiry tests.

e2e/map-interactions.spec.ts

@@ -14,7 +14,8 @@ const HUB = 'EDDF'; // must match HUB_ICAO in lib/game/seed.ts
 // land in ~2 s — shorter than the map poll + click pipeline). Round-trip burn (~4970 L) fits
 // the 6300 L tank, so a full-tank departure always makes it home.
 const DEST = 'LEMD';
-const SCALE = 1000; // fastest sim speed (v0.14.0 ladder top)
+const SCALE = 1000; // test rate for fast-forwarding legs
+const WORLD = 24; // the fixed world rate (ISS-117) — must match lib/worldClock.ts
 
 interface PlaneState {
   id: string;
@@ -40,7 +41,7 @@ interface PackageState {
 
 interface StateBody {
   account: { cash: number; reputation: number };
-  simState: { clockMs: number; timeScale: number; paused: boolean };
+  simState: { clockMs: number }; // ISS-117: the snapshot carries only the game clock
   planes: PlaneState[];
   packages: PackageState[];
 }
@@ -64,24 +65,18 @@ async function getState(page: Page): Promise<StateBody> {
   return (await res.json()) as StateBody;
 }
 
-async function postSim(page: Page, body: unknown) {
-  return page.request.post('/api/sim', { data: body });
-}
-
-// Set the time scale and VERIFY from the response that it stuck — a silent reset would
-// otherwise surface as an unexplained landing-wait timeout. ISS-041 also clears pause: a
-// landing pauses the sim, so any fast-forward after one must resume it or the clock stays frozen.
+// Test hook (FLIGHT_TEST_HOOKS=1): set the world rate and VERIFY from the response that it stuck —
+// a silent reset would otherwise surface as an unexplained landing-wait timeout.
 async function setScale(page: Page, scale: number): Promise<void> {
-  const res = await page.request.post('/api/sim', { data: { timeScale: scale, paused: false } });
+  const res = await page.request.post('/api/test/set-timescale', { data: { timeScale: scale } });
   expect(res.status()).toBe(200);
   const body = (await res.json()) as { timeScale: number };
-  expect(body.timeScale, `timeScale should be ${scale} after POST /api/sim`).toBe(scale);
+  expect(body.timeScale, `timeScale should be ${scale} after POST /api/test/set-timescale`).toBe(scale);
 }
 
-// Leave the live instance in a sane state for the other specs (scale 1, running).
+// Leave the live instance in a sane state for the other specs (the fixed world rate).
 test.afterEach(async ({ page }) => {
-  const res = await postSim(page, { timeScale: 1, paused: false });
-  expect(res.status()).toBe(200);
+  await setScale(page, WORLD);
 });
 
 // Test hook (FLIGHT_TEST_HOOKS=1): create an open package on a known route.
@@ -235,7 +230,7 @@ test('plane markers move while flying and the plane popup shows status + route',
   // 2) Fly the plane and speed up — its current leg must appear as a route line.
   const fly = await page.request.post('/api/planes/plane-starter/fly', { data: { destIcao: DEST } });
   expect(fly.status()).toBe(200);
-  await postSim(page, { timeScale: SCALE });
+  await setScale(page, SCALE);
 
   await expect
     .poll(async () => {
@@ -258,10 +253,11 @@ test('plane markers move while flying and the plane popup shows status + route',
   // The arc itself stays covered by unit tests: lib/mapData.test.ts.)
 
   // 4) Click the flying plane → status popup with model, status, fuel and the leg.
-  // Freeze the sim so the click can't miss a fast-moving marker: at scale 1000 the rendered
-  // marker lags our fresh /api/state fetch by up to one map poll (~1 s) — tens of px of drift
-  // on this leg. Pausing makes the position static; we resume right after the popup checks.
-  await postSim(page, { paused: true });
+  // Freeze the sim so the click can't miss a moving marker: at scale 1000 the rendered marker lags
+  // our fresh /api/state fetch by up to one map poll (~1 s). At scale 1 (and this continent-level
+  // view) the per-second drift is sub-pixel, so the position is static for all practical purposes;
+  // we restore SCALE right after the popup checks.
+  await setScale(page, 1);
   let prevPos: { lat: number; lon: number } | null = null;
   await expect
     .poll(async () => {
@@ -270,11 +266,11 @@ test('plane markers move while flying and the plane popup shows status + route',
       if (prevPos && prevPos.lat === p.lat && prevPos.lon === p.lon) return true;
       prevPos = { lat: p.lat, lon: p.lon };
       return false;
-    }, { timeout: 15_000, message: 'waiting for the paused clock to freeze the plane position' })
+    }, { timeout: 15_000, message: 'waiting for the scale-1 clock to settle the plane position' })
     .toBe(true);
 
-  // Click the RENDERED marker position, not a fresh /api/state fetch. With the sim paused
-  // above the server's analytic position is static — but the map renders from its own ~1 s
+  // Click the RENDERED marker position, not a fresh /api/state fetch. With the clock at scale 1
+  // above the server's analytic position barely moves — but the map renders from its own ~1 s
   // poll, so right after the freeze confirmation the last rendered frame can still be up to
   // one poll interval stale (tens of px at scale 1000 on this leg) and a click projected
   // from a fresh fetch misses the small circle layer (CI run #37). Poll for the plane's
@@ -314,8 +310,8 @@ test('plane markers move while flying and the plane popup shows status + route',
   // The popup's route line is the plane's own leg: origin name → destination name.
   await expect(page.getByTestId('plane-route')).toContainText(`${live.locationName} → ${live.destName}`);
 
-  // Resume before step 5 — the landing wait needs a running clock.
-  await postSim(page, { timeScale: SCALE, paused: false });
+  // Restore SCALE before step 5 — the landing wait needs a fast clock.
+  await setScale(page, SCALE);
 
   // 5) Let the flight finish, then fly home so the live instance stays in its
   // onboarding state (starter grounded at EDDF) for the other specs. The loaded