Broken planes cannot fly; repair heals gradually (ISS-089)

- flyPlane 409s a broken plane (health <= 0) before any refuel math — fuel/cash untouched
- engine auto-chain skips chaining when a landing's wear breaks the plane (queue kept intact)
- finishRepairs heals along round(f x 100) each tick; flip to available at exactly 100 on gate pass
- repairPlane no longer jumps health to 100 — it starts the gradual heal
- REMOVED BROKEN_BURN_MULTIPLIER / conditionBurnMultiplier and all burn sites (unreachable now)
- OpenAPI + route comments reworded; unit tests reworked; e2e maintenance.spec.ts per issue
- v0.45.0

lib/openapi.ts

@@ -223,7 +223,7 @@ export const openApiSpec = {
           },
           409: {
             description:
-              'Plane not grounded, or the leg does not fit even a FULL tank (v0.16.0 weight-proportional burn — the fuel required to cover the great-circle distance arriving empty; dispatch auto-refuels up to min(maxFuel, max(fuel, 1.5 × required)) first, ISS-082), or cash is insufficient for that top-up',
+              'Plane not grounded, plane broken (health ≤ 0 — repair it first, v0.45.0), or the leg does not fit even a FULL tank (v0.16.0 weight-proportional burn — the fuel required to cover the great-circle distance arriving empty; dispatch auto-refuels up to min(maxFuel, max(fuel, 1.5 × required)) first, ISS-082), or cash is insufficient for that top-up',
             content: { 'application/json': { schema: { $ref: '#/components/schemas/Error' } } },
           },
         },
@@ -233,7 +233,7 @@ export const openApiSpec = {
       post: {
         summary: 'Queue a flight leg for a plane',
         description:
-          'Append a NOT-yet-started leg to the plane\'s flight queue (v0.25.0, ISS-043). Works whether the plane is grounded or flying — you can pre-build a route; the active leg still starts via /fly and nothing auto-starts here. On landing, the engine auto-chains the first queued leg when fuel covers it — with a short tank it auto-refuels to 150% of the requirement (capped at tank capacity) when cash allows (ISS-082); only an unaffordable top-up grounds the plane with the queue kept intact for a later dispatch.',
+          'Append a NOT-yet-started leg to the plane\'s flight queue (v0.25.0, ISS-043). Works whether the plane is grounded or flying — you can pre-build a route; the active leg still starts via /fly and nothing auto-starts here. On landing, the engine auto-chains the first queued leg when fuel covers it and the plane is not broken by the landing\'s wear (v0.45.0) — with a short tank it auto-refuels to 150% of the requirement (capped at tank capacity) when cash allows (ISS-082); only an unaffordable top-up (or a broken plane) grounds the plane with the queue kept intact for a later dispatch.',
         operationId: 'queueLeg',
         parameters: [
           { name: 'planeId', in: 'path', required: true, schema: { type: 'string' } },
@@ -370,14 +370,14 @@ export const openApiSpec = {
       post: {
         summary: 'Repair a grounded plane',
         description:
-          'Restore a worn-out plane to full health for the flat repair cost (v0.39.0, ISS-069): the plane is grounded in "repairing" status until 3 sim days pass, when the engine\'s tick flips it back to "available". While repairing it cannot load, fly or be sold; a broken plane (health ≤ 0) still flies but burns 50% more fuel. A full-health repair is a free no-op (cost 0). No body.',
+          'Ground a worn-out plane in "repairing" status for the flat repair cost (v0.39.0, ISS-069): its health climbs back to 100 over 3 sim days — the engine\'s tick applies the curve each tick and flips it back to "available" exactly when full health is reached (v0.45.0, ISS-089). While repairing it cannot load, fly or be sold; a broken plane (health ≤ 0) cannot fly at all until repaired. A full-health repair is a free no-op (cost 0). No body.',
         operationId: 'repairPlane',
         parameters: [
           { name: 'planeId', in: 'path', required: true, schema: { type: 'string' } },
         ],
         responses: {
           200: {
-            description: 'Repair started (or free no-op) — full state snapshot (health 100, status "repairing" with the gate set, cash reduced by the flat cost)',
+            description: 'Repair started (or free no-op) — full state snapshot (status "repairing" with the gate set, health unchanged until the engine\'s tick heals it back to 100 over the duration, cash reduced by the flat cost)',
             content: { 'application/json': { schema: { $ref: '#/components/schemas/StateSnapshot' } } },
           },
           404: {
@@ -594,7 +594,7 @@ export const openApiSpec = {
           health: {
             type: 'number',
             description:
-              'Structural health in [0, 100] (v0.39.0) — wears down by a fixed amount per km of landed legs; at 0 the plane is broken and burns 50% more fuel until repaired.',
+              'Structural health in [0, 100] (v0.39.0) — wears down by a fixed amount per km of landed legs; at 0 the plane is broken and cannot fly until repaired (v0.45.0). While "repairing" this doubles as repair progress: it climbs back to 100 over the repair duration.',
           },
           repairUntilSimTime: {
             type: ['integer', 'null'],