Package weight, payload capacity and per-kg payout (ISS-045)

Packages carry a real weightKg (unit weight x count with +/-30% jitter),
plane capacity becomes maxPayloadKg instead of 6 slots, load validation
sums cargo weight against the payload, and the payout gains a per-kg part.
Loadout display shows tonnage; OpenAPI swaps CatalogEntry.capacity for
maxPayloadKg and adds PackageState.weightKg.

app/api/packages/[id]/load/route.ts

@@ -1,10 +1,11 @@
 import { loadPackage, performAction } from '@/lib/game/actions';
 
 // POST /api/packages/:id/load (v0.12.0) — body { planeId: string }. Loads an OPEN
-// package onto a GROUNDED plane at the package's origin with a free slot. 400
-// missing/non-string planeId or unknown fields; 404 unknown package/plane id; 409
-// wrong package status, plane flying, plane not at the origin, no free slots. On
-// success returns the full state snapshot (package now "loaded" on that plane).
+// package onto a GROUNDED plane at the package's origin with enough payload room
+// for its weight (v0.27.0). 400 missing/non-string planeId or unknown fields; 404
+// unknown package/plane id; 409 wrong package status, plane flying, plane not at
+// the origin, no payload room. On success returns the full state snapshot
+// (package now "loaded" on that plane).
 
 export async function POST(req: Request, ctx: { params: Promise<{ id: string }> }) {
   const { id } = await ctx.params;

app/api/state/route.test.ts

@@ -58,7 +58,7 @@ describe('GET /api/state', () => {
 
     const packages = body.packages as Array<Record<string, unknown>>;
     expect(packages.length).toBeGreaterThan(0);
-    for (const key of ['id', 'originIcao', 'destIcao', 'reward', 'cargoType', 'deadlineSimTime', 'status']) {
+    for (const key of ['id', 'originIcao', 'destIcao', 'reward', 'cargoType', 'weightKg', 'deadlineSimTime', 'status']) {
       expect(packages[0], `package.${key}`).toHaveProperty(key);
     }
   });
@@ -86,7 +86,7 @@ describe('GET /api/state', () => {
       expect(entry.maxFuel).toBe(type.maxFuel);
       expect(entry.burnPerKm).toBe(type.burnPerKm);
       expect(entry.speedKmh).toBe(type.speedKmh);
-      expect(entry.capacity).toBe(type.capacity); // v0.12.0 slot capacity (ATR 72-600: 6)
+      expect(entry.maxPayloadKg).toBe(type.maxPayloadKg); // v0.27.0 payload kg (ATR 72-600: 4800)
     }
 
     // Economy constants — the single source of truth stays lib/game/catalog.ts.

app/api/test/create-package/route.ts

@@ -14,11 +14,13 @@ import { tickNow } from '@/lib/sim/engine';
 // same gate, same conventions.
 //
 // POST /api/test/create-package
-//   body { originIcao?: string, destIcao?: string, deadlineOffsetMs?: number }
+//   body { originIcao?: string, destIcao?: string, deadlineOffsetMs?: number, weightKg?: number }
 //   - ICACOs must exist in the airport dataset and differ (400 otherwise);
 //     omitted endpoints are picked at random by generatePackage.
 //   - deadlineOffsetMs defaults to a normal 6–72h game-time window (NOT the short
 //     hook deadline of expire-package) — pass an explicit value to override.
+//   - weightKg (v0.27.0) forces the package weight instead of the RNG draw, so e2e
+//     flows that load several packages can stay under the plane's payload deterministically.
 //   Returns 201 + the created package row.
 
 export async function POST(req: Request) {
@@ -38,7 +40,7 @@ export async function POST(req: Request) {
   }
   const input = body as Record<string, unknown>;
   for (const key of Object.keys(input)) {
-    if (key !== 'originIcao' && key !== 'destIcao' && key !== 'deadlineOffsetMs') {
+    if (key !== 'originIcao' && key !== 'destIcao' && key !== 'deadlineOffsetMs' && key !== 'weightKg') {
       return Response.json({ error: `unknown field "${key}"` }, { status: 400 });
     }
   }
@@ -50,6 +52,9 @@ export async function POST(req: Request) {
   if (input.deadlineOffsetMs !== undefined && (typeof input.deadlineOffsetMs !== 'number' || !Number.isFinite(input.deadlineOffsetMs))) {
     return Response.json({ error: 'deadlineOffsetMs must be a finite number' }, { status: 400 });
   }
+  if (input.weightKg !== undefined && (typeof input.weightKg !== 'number' || !Number.isFinite(input.weightKg) || input.weightKg <= 0)) {
+    return Response.json({ error: 'weightKg must be a positive finite number' }, { status: 400 });
+  }
 
   try {
     const inst = await getGameDb();
@@ -79,6 +84,7 @@ export async function POST(req: Request) {
       deadlineOffsetMs: input.deadlineOffsetMs as number | undefined,
       originIcao: input.originIcao as string | undefined,
       destIcao: input.destIcao as string | undefined,
+      weightKg: input.weightKg as number | undefined,
     });
     await inst.db.insert(schema.packages).values(created);
     await persist(inst);