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>

pnpm-lock.yaml

@@ -117,6 +117,28 @@ importers:
         specifier: ^5.8.0
         version: 5.9.3
 
+  packages/game-simulation:
+    dependencies:
+      '@ai-tycoon/game-engine':
+        specifier: workspace:*
+        version: link:../game-engine
+      '@ai-tycoon/shared':
+        specifier: workspace:*
+        version: link:../shared
+    devDependencies:
+      '@ai-tycoon/tsconfig':
+        specifier: workspace:*
+        version: link:../tsconfig
+      '@types/node':
+        specifier: ^22.0.0
+        version: 22.19.17
+      tsx:
+        specifier: ^4.19.4
+        version: 4.21.0
+      typescript:
+        specifier: ^5.8.0
+        version: 5.9.3
+
   packages/shared:
     devDependencies:
       '@ai-tycoon/tsconfig':
@@ -923,6 +945,9 @@ packages:
   '@types/estree@1.0.8':
     resolution: {integrity: sha512-dWHzHa2WqEXI/O1E9OjrocMTKJl2mSrEolh1Iomrv6U+JuNwaHXsXx9bLu5gG7BUWFIN0skIQJQ/L1rIex4X6w==}
 
+  '@types/node@22.19.17':
+    resolution: {integrity: sha512-wGdMcf+vPYM6jikpS/qhg6WiqSV/OhG+jeeHT/KlVqxYfD40iYJf9/AE1uQxVWFvU7MipKRkRv8NSHiCGgPr8Q==}
+
   '@types/node@25.6.0':
     resolution: {integrity: sha512-+qIYRKdNYJwY3vRCZMdJbPLJAtGjQBudzZzdzwQYkEPQd+PJGixUL5QfvCLDaULoLv+RhT3LDkwEfKaAkgSmNQ==}
 
@@ -1567,6 +1592,9 @@ packages:
     engines: {node: '>=14.17'}
     hasBin: true
 
+  undici-types@6.21.0:
+    resolution: {integrity: sha512-iwDZqg0QAGrg9Rav5H4n0M64c3mkR59cJ6wQp+7C4nI0gsmExaedaYLNO44eT4AtBBwjbTiGPMlt2Md0T9H9JQ==}
+
   undici-types@7.19.2:
     resolution: {integrity: sha512-qYVnV5OEm2AW8cJMCpdV20CDyaN3g0AjDlOGf1OW4iaDEx8MwdtChUp4zu4H0VP3nDRF/8RKWH+IPp9uW0YGZg==}
 
@@ -2176,6 +2204,10 @@ snapshots:
 
   '@types/estree@1.0.8': {}
 
+  '@types/node@22.19.17':
+    dependencies:
+      undici-types: 6.21.0
+
   '@types/node@25.6.0':
     dependencies:
       undici-types: 7.19.2
@@ -2788,6 +2820,8 @@ snapshots:
 
   typescript@5.9.3: {}
 
+  undici-types@6.21.0: {}
+
   undici-types@7.19.2: {}
 
   update-browserslist-db@1.2.3(browserslist@4.28.2):