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/hover.spec.ts

@@ -11,7 +11,8 @@ import { test, expect, type Page } from '@playwright/test';
 // cargo rows and the Relocate section; the relocate preview rings only its TARGET airport, which
 // additionally gets a distinct green ring in `airports-target-highlight` (ISS-022).
 
-const SCALE = 1000; // fastest sim speed (v0.14.0 ladder top) — keeps flights to seconds of real time
+const SCALE = 1000; // test rate for fast-forwarding legs — keeps flights to seconds of real time
+const WORLD = 24; // the fixed world rate (ISS-117) — must match lib/worldClock.ts
 const HUB = 'EDDF'; // must match HUB_ICAO in lib/game/seed.ts
 // Madrid–Barajas — same long leg as e2e/map-interactions.spec.ts: ~1420 km → ~10 s at scale 1000.
 const DEST = 'LEMD';
@@ -41,7 +42,7 @@ 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[];
 }
@@ -52,24 +53,18 @@ 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.
@@ -106,8 +101,7 @@ async function flyHomeViaApi(page: Page): Promise<void> {
       .toBe(true);
   }
   if (starter.locationIcao !== HUB) {
-    // ISS-041: the landing above paused the sim — setScale clears pause so the return leg
-    // fast-forwards instead of taking real-time hours.
+    // Make sure the world rate is back at SCALE so the return leg fast-forwards.
     await setScale(page, SCALE);
     const res = await page.request.post('/api/planes/plane-starter/fly', { data: { destIcao: HUB } });
     expect(res.status()).toBe(200); // repositioning needs no package (v0.12.0 manual flight)
@@ -472,8 +466,9 @@ test('hovering the fleet row of a flying plane highlights its route', async ({ p
   await expect(block).toContainText(/in flight/i, { timeout: 15_000 });
 
   // Freeze mid-flight so the ~10 s leg can't land under us while we assert (same pattern as
-  // e2e/map-interactions.spec.ts' marker click): the route line stays drawn while paused.
-  await postSim(page, { paused: true });
+  // e2e/map-interactions.spec.ts' marker click): at scale 1 the leg takes minutes of real time, and
+  // the route line stays drawn while frozen.
+  await setScale(page, 1);
 
   await block.hover();
   await expect.poll(async () => {
@@ -489,7 +484,7 @@ test('hovering the fleet row of a flying plane highlights its route', async ({ p
 
   // Resume and fast-forward to arrival, then fly home so the live instance stays in its
   // onboarding state (starter grounded at EDDF) for the other specs.
-  await postSim(page, { timeScale: SCALE, paused: false });
+  await setScale(page, SCALE);
   await expect
     .poll(async () => {
       const p = (await getState(page)).planes.find((x) => x.id === 'plane-starter');
@@ -497,7 +492,7 @@ test('hovering the fleet row of a flying plane highlights its route', async ({ p
     }, { timeout: 120_000, message: `waiting for plane-starter to land at ${DEST}` })
     .toBe(true);
 
-  // ISS-041: the arrival above paused the sim, so re-set SCALE for this leg (setScale clears pause).
+  // Re-set SCALE for the return leg.
   await setScale(page, SCALE);
   const home = await page.request.post('/api/planes/plane-starter/fly', { data: { destIcao: HUB } });
   expect(home.status()).toBe(200);
@@ -535,10 +530,10 @@ test('hovering an on-board package while its carrier is mid-flight traces from t
   expect(flyBody.planes.find((p) => p.id === 'plane-starter')?.status).toBe('flying');
 
   // Freeze immediately: at a leftover scale of 1000 the ~10 s leg could otherwise land under us and
-  // auto-chain the queued EHAM leg, which would change (or empty) the trace while we assert. Paused,
-  // every /api/state snapshot reports the same state — and the new rule's start point is the LANDING
-  // airport regardless of progress, so no mid-flight position window is needed at all.
-  await postSim(page, { paused: true });
+  // auto-chain the queued EHAM leg, which would change (or empty) the trace while we assert. At
+  // scale 1 every /api/state snapshot reports the same state for minutes — and the new rule's start
+  // point is the LANDING airport regardless of progress, so no mid-flight position window is needed at all.
+  await setScale(page, 1);
 
   const row = page.locator(`[data-testid="onboard-package-${pkg.id}"]`);
   await expect(row, 'the loaded package appears in the On board section').toBeVisible({ timeout: 15_000 });
@@ -584,7 +579,7 @@ test('hovering an on-board package while its carrier is mid-flight traces from t
   // not DEST — it never delivered), then fly home.
   const cancelRes = await page.request.post('/api/planes/plane-starter/queue/cancel', { data: { index: 0 } });
   expect(cancelRes.status()).toBe(200);
-  await setScale(page, SCALE); // also clears the pause above
+  await setScale(page, SCALE);
   await expect
     .poll(async () => {
       const p = (await getState(page)).planes.find((x) => x.id === 'plane-starter');
@@ -595,7 +590,7 @@ test('hovering an on-board package while its carrier is mid-flight traces from t
   const abandon = await page.request.post(`/api/packages/${pkg.id}/abandon`);
   expect(abandon.status()).toBe(200); // only possible once grounded — the poll above guarantees it
 
-  // ISS-041: the arrival above paused the sim, so re-set SCALE for this leg (setScale clears pause).
+  // Re-set SCALE for the return leg.
   await setScale(page, SCALE);
   const home = await page.request.post('/api/planes/plane-starter/fly', { data: { destIcao: HUB } });
   expect(home.status()).toBe(200);