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.

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## v0.52.0 — 2026-09-22 10:45
+- **Fixed world clock, no player time controls (ISS-117).** The pause button and the 1×–1000× scale slider are gone from the left pane (`components/LeftPane.tsx`) — the world now always runs at a fixed `WORLD_TIME_SCALE = 24` (new client-safe `lib/worldClock.ts`, re-exported by the engine). The server advances time in a background tick: new `instrumentation.ts` starts `startBackgroundTick()` (1 s interval, singleton-guarded) under `NEXT_RUNTIME === 'nodejs'`, so the sim moves even with no open browser. **Idle-pause:** while no plane is flying or in repair the clock is frozen exactly — pure `shouldAdvanceTime(planes)` in `lib/sim/engine.ts` gates every tick (no catch-up jump on wake; `lastRealTickMs` still updates). Fresh worlds start at year 2000 (`STARTING_CLOCK_MS = Date.UTC(2000, 0, 1)` in `lib/game/seed.ts`; existing saves untouched — no migration). The client clock (`lib/useSimClock.ts`) extrapolates between polls at the fixed rate and freezes while idle, mirroring the server.
+- **API.** `POST /api/sim` deleted (route + OpenAPI entry; spec now lists twelve endpoints) and its controls removed from the engine (`applyTimeControls`, `clampTimeScale`, MIN/MAX_TIME_SCALE). The `/api/state` snapshot's `simState` is now `{ clockMs }` only — no `timeScale`/`paused`. New test-only hook `POST /api/test/set-timescale` behind the existing `FLIGHT_TEST_HOOKS=1` gate (sibling of `/api/test/set-health`, same 404-when-disabled convention): body `{ timeScale: finite number in [1, 100_000] }` else 400; ticks first under the sim lock and returns `{ clockMs, timeScale }`. The e2e suite's per-spec `setScale` helpers now call it (and verify from the response); every spec restores the world rate in `afterEach`.
+- **Tests.** Unit: engine tests re-anchored to `STARTING_CLOCK_MS` with a `makeWorldActive` helper (fresh DBs seed a grounded starter, so advancing-world tests put one in flight first) plus new idle-pause coverage (`shouldAdvanceTime` synthetic arrays; grounded fleet freezes the clock exactly; repairing keeps it advancing); actions/seed/db/openapi tests re-anchored to the year-2000 origin and fixed world rate; `lib/timeScale.ts`, its test, `components/left-pane.test.ts` and the old `/api/sim` route + test deleted. E2E: all specs rewritten off `POST /api/sim` — pause tests replaced by idle-pause assertions (e.g. `right-pane.spec.ts` verifies a double-read 1.5 s apart that a grounded fleet freezes the clock exactly, which also makes its penalty-preview math deterministic); `sim.spec.ts` activates the world via set-health + `/repair` for its advance/expiry tests and pins the new hook's validation; `panes.spec.ts` drops the slider-commit test (controls gone) and samples the smooth client clock at the fixed 24× rate, asserting the pause/slider testids are absent; `state.spec.ts` restart test self-heals to a fully grounded fleet first and now asserts the post-restart clock is byte-identical (frozen across the restart); `two-planes.spec.ts` loses its ISS-057 slow-on-landing assertions — the auto-chain observation leg now flies at world rate so polls can see it; `api.spec.ts` endpoint list drops `/api/sim` (thirteen → twelve).
+
 ## v0.51.0 — 2026-09-22 08:21
 - **Max range display is now guaranteed flyable in all weather (ISS-099).** The spec card's "Max range" (`components/RightPane.tsx`) showed `maxRangeKm` — the weighted-model closed form with NO wind — while dispatch's fuel guard (`flyPlane`, and the engine's auto-chain) uses wind-adjusted burn (up to +20% headwind, v0.36.0), so a leg inside the displayed range could 409 "insufficient fuel" when the departure airport had a headwind. New `MAX_WIND_BURN_FACTOR` (= 1.2 — pinned in tests to be exactly `windBurnFactor`'s maximum) and `guaranteedRangeKm(burnPerKm, emptyWeightKg, maxFuel)` = `maxRangeKm` under worst-case headwind burn (`lib/sim/movement.ts`). The UI now shows the guaranteed range: any leg within it is flyable in all weather. ATR 72-600: 4436 → 3696 km; Boeing 777: 13045 → 10871 km — matching the `maxRangeKm ÷ 1.2` convention seed.ts already uses for its job-generation cap
 - **Tests.** Unit +15: new `guaranteedRangeKm` block in `lib/sim/movement.test.ts` (3 tests — MAX_WIND_BURN_FACTOR pinned to `windBurnFactor(30, 90, 90)`, ATR ≈ 3697 km ±5%, zero-fuel/invalid-weight guards) and a per-type consistency loop in `lib/game/catalog.test.ts` (12 tests — for ALL six catalog types: `requiredFuelFor(guaranteed range)` ≤ maxFuel under worst-case headwind, tightness at 1.05× > maxFuel, and the no-wind closed form still an exact inverse). E2E: `e2e/right-pane.spec.ts` market-tab test now imports and asserts `guaranteedRangeKm` directly (local mirror deleted)