Flight queue backend: planes hold a queue of upcoming legs, auto-chain on landing (ISS-043 part 1)

- planes.queue TEXT NOT NULL DEFAULT '[]' — ordered JSON array of not-yet-started
  leg ICACs; active leg stays destIcao + departureSimTime. DDL + guarded ALTER
  migration for existing DBs; seed sets queue: [] explicitly.
- deliverPackages() auto-chains on arrival: with a non-empty queue and fuel
  covering the first queued leg (same requiredFuelFor rule as /fly), the plane
  immediately starts that leg from the arrival airport (stays 'flying',
  departureSimTime = arrival instant, queue shortened). Short tank → grounds
  safely with the queue kept intact; empty queue → unchanged grounding. Cargo
  delivery for the reached airport runs first and is unaffected. Ordering kept:
  delivery still runs before tickOnce's pause check, so a chained plane counts
  as still flying — no premature last-plane pause (ISS-041 preserved).
- New endpoints via performAction(): POST /api/planes/{planeId}/queue {destIcao}
  (append; works grounded or flying; 400 bad body/unknown ICAO, 404 unknown
  plane) and POST /api/planes/{planeId}/queue/cancel {index} (remove queued leg
  by index; active in-flight leg never affected; 400 non-integer/out-of-range,
  404 unknown plane). Both return the full state snapshot.
- PlaneState.queue: string[] in /api/state (null/malformed-safe parse helper
  shared with the engine); OpenAPI updated (PlaneState.queue, QueueLegRequest,
  CancelQueuedLegRequest, both paths) and openapi.test.ts expectations extended.
- Tests: auto-chain block in engine.test.ts (chain / short-fuel ground / empty
  queue) + chained-plane-no-pause regression guard; queueLeg/cancelQueuedLeg
  blocks in actions.test.ts; type-compat queue: [] fixtures in deriveEvents,
  right-pane, mapData and seed tests.

v0.25.0 — part 1 (backend) of ISS-043; UI/map rendering lands in a follow-up.

CHANGELOG.md

@@ -1,5 +1,13 @@
 # Changelog
 
+## v0.25.0 — 2026-09-20 10:36
+- **Planes now hold a queue of upcoming flight legs (ISS-043, part 1 — backend).** One new column on `planes`: `queue TEXT NOT NULL DEFAULT '[]'` (`lib/db/schema.ts`, DDL + guarded `ALTER TABLE` migration in `lib/db/client.ts`) storing an ordered JSON array of ICAO strings = the legs NOT yet started. The active leg stays exactly as before (`destIcao` + `departureSimTime`); full path = `[locationIcao, destIcao, ...queue]`. No new table — queues are short, per-plane, always read/written whole
+- **Auto-chain on landing (ISS-043).** In `deliverPackages()` (`lib/sim/engine.ts`) a plane that arrives now reads its queue: if it holds legs AND fuel covers the first one (same `requiredFuelFor` feasibility rule as `/fly`), it immediately starts that leg from the arrival airport — stays `'flying'`, `departureSimTime` = the arrival instant, queue shortened. If fuel is short it grounds safely with the remaining queue kept intact for refuel + re-dispatch; an empty queue grounds exactly as before. Cargo delivery for the reached airport runs first and is unaffected by chaining. Ordering preserved on purpose: delivery runs BEFORE tickOnce's pause check (ISS-041), so a chained plane counts as still flying there — chaining never triggers the last-plane pause
+- **New endpoints (ISS-043).** `POST /api/planes/{planeId}/queue` body `{destIcao}` appends a not-yet-started leg (works grounded or flying — pre-build a route; nothing auto-starts, 400 unknown ICAO/bad body, 404 unknown plane); `POST /api/planes/{planeId}/queue/cancel` body `{index}` removes a queued leg by index (only queued legs are cancellable — the active in-flight leg is never touched; 400 non-integer/out-of-range index, 404 unknown plane). Both run through `performAction()` like every other action and return the full state snapshot. New actions `queueLeg`/`cancelQueuedLeg` in `lib/game/actions.ts`; routes under `app/api/planes/[planeId]/queue/`
+- **Snapshot + spec (ISS-043).** `PlaneState.queue: string[]` added to the `/api/state` snapshot (`lib/game/state.ts`, parsed with a null/malformed-safe helper shared by the engine); OpenAPI updated — `PlaneState.queue`, `QueueLegRequest`, `CancelQueuedLegRequest`, both new paths (200→snapshot, 400, 404)
+- Tests: unit — `lib/sim/engine.test.ts`: auto-chain block in `deliverPackages` (lands with queue + enough fuel → `'flying'` to the next dest at the arrival instant with the queue shortened; lands short on fuel → grounds with the queue intact; empty queue → unchanged grounding) plus a pause-on-landing regression guard — a chained plane does NOT trigger the last-plane pause. `lib/game/actions.test.ts`: `queueLeg` (appends in order, works while flying without touching the active leg, 404 unknown plane, 400 unknown ICAO) and `cancelQueuedLeg` (removes the right index keeping order, 400 out-of-range/negative/empty-queue, 404 unknown plane). `lib/openapi.test.ts`: endpoint count ten → twelve, PlaneState keys + both request schemas. Type-compat only: `queue: []` added to the `PlaneState`/seed fixtures in `deriveEvents`, `right-pane`, `mapData`, `seed` tests
+- Part 1 of ISS-043 (backend) — UI/map rendering of queued legs lands in a follow-up part. Verified: `tsc --noEmit` clean; unit suite green locally; `npx playwright test --list` unchanged at 42 tests in 12 files; e2e not run locally by design — CI verifies against an isolated stack
+
 ## v0.24.0 — 2026-09-20 09:48
 - **Landing now pauses the sim instead of auto-slowing to 1× (ISS-041).** When the LAST plane in flight lands, `tickOnce` (`lib/sim/engine.ts`) sets `sim_state.paused = true` WITHOUT touching `timeScale` — speed is preserved. The trigger condition carries over from ISS-011's auto-slow unchanged: ≥1 landing this tick AND no `'flying'` planes remain (a landing while another plane is still airborne does not pause — there would be nothing to auto-resume it). No idle-enforcement or auto-restore of the pause exists
 - **Starting a flight auto-resumes a paused sim (ISS-041).** `flyPlane()` (`lib/game/actions.ts`) writes `sim_state.paused = false` before persisting — inside `runAction()`, so tick + unpause + dispatch are atomic under the sim lock. The cycle: dispatch unpauses → last landing pauses (speed preserved) → next dispatch unpauses again