Add game-simulation package with multi-run balance testing, fix stalled-pipeline trap

Adds a full simulation harness (game-simulation package) with greedy/random strategies,
36-metric diagnostics, multi-run orchestration via child processes, and a statistical
interpreter. Includes 2.3x engine performance optimizations (research bonus caching,
per-DC dirty tracking, reduced allocations in tick pipeline, single-pass loops).

Fixes a critical balance bug where training pipelines stalled on insufficient VRAM would
permanently block training slots — the engine never re-checked stalled pipelines, and the
greedy strategy didn't pre-check VRAM requirements. This caused 20-25% of seeds to get
stuck in Scale-up era. All three fixes (engine un-stalling, strategy VRAM pre-check,
stalled pipeline cancellation) bring pass rate from 75% to 100% across 20 random seeds.

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

packages/game-simulation/package.json

@@ -0,0 +1,30 @@
+{
+  "name": "@ai-tycoon/game-simulation",
+  "private": true,
+  "version": "0.0.1",
+  "type": "module",
+  "main": "./src/simulate.ts",
+  "types": "./src/simulate.ts",
+  "scripts": {
+    "simulate": "tsx src/simulate.ts",
+    "simulate:greedy": "tsx src/simulate.ts --strategy greedy --ticks 28800",
+    "simulate:random": "tsx src/simulate.ts --strategy random --ticks 28800",
+    "simulate:ci": "tsx src/simulate.ts --strategy greedy --ticks 28800 --json --csv --seed 42",
+    "multirun": "tsx src/multirun.ts",
+    "multirun:quick": "tsx src/multirun.ts --runs 5 --parallel 4 --strategy greedy --ticks 28800",
+    "multirun:full": "tsx src/multirun.ts --runs 20 --parallel 4 --strategy greedy --ticks 28800",
+    "interpret": "tsx src/interpret.ts",
+    "build": "tsc",
+    "typecheck": "tsc --noEmit"
+  },
+  "dependencies": {
+    "@ai-tycoon/shared": "workspace:*",
+    "@ai-tycoon/game-engine": "workspace:*"
+  },
+  "devDependencies": {
+    "@ai-tycoon/tsconfig": "workspace:*",
+    "@types/node": "^22.0.0",
+    "tsx": "^4.19.4",
+    "typescript": "^5.8.0"
+  }
+}