Fix OOM in CI: make WorldCupSimulator simulation count configurable for tests

Tests now pass numSimulations=500 instead of the production default of 50,000.
Six simulator tests × 50k iterations each was exhausting the 4GB heap on GitHub
Actions runners. Also reduce simGroupMatch stat tests from 50k to 5k iterations.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/services/simulations/__tests__/world-cup-simulator.test.ts

@@ -17,31 +17,31 @@ describe("simGroupMatch", () => {
 
   it("equal teams draw ≈28% of the time", () => {
     let draws = 0;
-    const N = 50_000;
+    const N = 5_000;
     for (let i = 0; i < N; i++) {
       if (simGroupMatch(1500, 1500) === "draw") draws++;
     }
     const drawRate = draws / N;
-    // BASE_DRAW_RATE = 0.28 at eloDiff=0; accept ±3% from sampling noise
+    // BASE_DRAW_RATE = 0.28 at eloDiff=0; accept ±5% from sampling noise at N=5k
-    expect(drawRate).toBeGreaterThan(0.25);
+    expect(drawRate).toBeGreaterThan(0.23);
-    expect(drawRate).toBeLessThan(0.31);
+    expect(drawRate).toBeLessThan(0.33);
   });
 
   it("draw rate decays with large Elo gap", () => {
     let draws = 0;
-    const N = 50_000;
+    const N = 5_000;
     for (let i = 0; i < N; i++) {
       if (simGroupMatch(2000, 1400) === "draw") draws++;
     }
     const drawRate = draws / N;
-    // eloDiff = 600 → pDraw ≈ 0.28 * exp(-1.2) ≈ 0.084; accept ±3%
+    // eloDiff = 600 → pDraw ≈ 0.28 * exp(-1.2) ≈ 0.084; accept ±5%
-    expect(drawRate).toBeLessThan(0.13);
+    expect(drawRate).toBeLessThan(0.15);
   });
 
   it("strong favorite wins more often than underdog", () => {
     let wins = 0;
     let losses = 0;
-    const N = 50_000;
+    const N = 5_000;
     for (let i = 0; i < N; i++) {
       const r = simGroupMatch(1900, 1600);
       if (r === "win") wins++;
@@ -110,7 +110,7 @@ describe("WorldCupSimulator", () => {
     mockDb.query.tournamentGroups.findMany.mockResolvedValue([]);
     mockDb.query.playoffMatches.findMany.mockResolvedValue([]);
 
-    const sim = new WorldCupSimulator();
+    const sim = new WorldCupSimulator(500);
     await expect(sim.simulate("season-1")).rejects.toThrow("No participants found");
   });
 
@@ -121,7 +121,7 @@ describe("WorldCupSimulator", () => {
     mockDb.query.tournamentGroups.findMany.mockResolvedValue([]);
     mockDb.query.playoffMatches.findMany.mockResolvedValue([]);
 
-    const sim = new WorldCupSimulator();
+    const sim = new WorldCupSimulator(500);
     const results = await sim.simulate("season-1");
     expect(results).toHaveLength(48);
     const ids = new Set(results.map((r) => r.participantId));
@@ -137,7 +137,7 @@ describe("WorldCupSimulator", () => {
     mockDb.query.tournamentGroups.findMany.mockResolvedValue([]);
     mockDb.query.playoffMatches.findMany.mockResolvedValue([]);
 
-    const sim = new WorldCupSimulator();
+    const sim = new WorldCupSimulator(500);
     const results = await sim.simulate("season-1");
 
     const sumFirst  = results.reduce((s, r) => s + r.probabilities.probFirst,  0);
@@ -158,7 +158,7 @@ describe("WorldCupSimulator", () => {
     mockDb.query.tournamentGroups.findMany.mockResolvedValue([]);
     mockDb.query.playoffMatches.findMany.mockResolvedValue([]);
 
-    const sim = new WorldCupSimulator();
+    const sim = new WorldCupSimulator(500);
     const results = await sim.simulate("season-1");
 
     for (const r of results) {
@@ -179,7 +179,7 @@ describe("WorldCupSimulator", () => {
     mockDb.query.tournamentGroups.findMany.mockResolvedValue([]);
     mockDb.query.playoffMatches.findMany.mockResolvedValue([]);
 
-    const sim = new WorldCupSimulator();
+    const sim = new WorldCupSimulator(500);
     const results = await sim.simulate("season-1");
 
     // probFirst + probSecond + probThird + probFourth should cover all probability mass
@@ -235,7 +235,7 @@ describe("WorldCupSimulator", () => {
     mockDb.query.tournamentGroups.findMany.mockResolvedValue([group, ...remainingGroups]);
     mockDb.query.playoffMatches.findMany.mockResolvedValue([]);
 
-    const sim = new WorldCupSimulator();
+    const sim = new WorldCupSimulator(500);
     const results = await sim.simulate("season-1");
 
     const p3Result = results.find((r) => r.participantId === "p3");
@@ -255,7 +255,7 @@ describe("WorldCupSimulator", () => {
     mockDb.query.tournamentGroups.findMany.mockResolvedValue([]);
     mockDb.query.playoffMatches.findMany.mockResolvedValue([]);
 
-    const sim = new WorldCupSimulator();
+    const sim = new WorldCupSimulator(500);
     const results = await sim.simulate("season-1");
 
     for (const r of results) {

app/services/simulations/world-cup-simulator.ts

@@ -303,6 +303,12 @@ function normalizeProbabilities(
 // ─── Main simulator ───────────────────────────────────────────────────────────
 
 export class WorldCupSimulator implements Simulator {
+  private readonly numSimulations: number;
+
+  constructor(numSimulations = NUM_SIMULATIONS) {
+    this.numSimulations = numSimulations;
+  }
+
   async simulate(sportsSeasonId: string): Promise<SimulationResult[]> {
     const db = database();
 
@@ -465,7 +471,7 @@ export class WorldCupSimulator implements Simulator {
       counts.qfLoser.set(id, 0);
     }
 
-    for (let sim = 0; sim < NUM_SIMULATIONS; sim++) {
+    for (let sim = 0; sim < this.numSimulations; sim++) {
       // ── Group stage ──────────────────────────────────────────────
       const advancingFromGroup: string[] = []; // group winners + runners-up (24 teams)
       const thirdPlaceTeams: TeamStats[] = [];  // 12 third-place teams
@@ -570,7 +576,7 @@ export class WorldCupSimulator implements Simulator {
     }
 
     // 8. Convert counts to probabilities
-    const N = NUM_SIMULATIONS;
+    const N = this.numSimulations;
     const numQfLosers = 4; // 4 QF losers per sim
 
     const results: SimulationResult[] = participantIds.map((id) => {