Multi-core simulation: grain movement and heat across a worker pool (t88 phase 3)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

test/t_gpu.py

@@ -23,7 +23,7 @@ with launch(viewport={'width':960,'height':600}) as (_,pg,url):
     assert startup['warm']>=0
     print('PASS both looks submit behind loading screen; first visible frame ms',startup)
     pg.add_script_tag(path=str(root/'tools/perf-scenes.js'))
-    pg.evaluate("perfScene('factory',1024,640); SET.look='pixel'; SET.zoom=2;resizeRender();snapCamera();drawWorld();")
+    pg.evaluate("async()=>{perfScene('factory',1024,640);await startThreads();simPool.force=true;SET.look='pixel';SET.zoom=2;resizeRender();snapCamera();drawWorld();}")
     result=pg.evaluate('''async () => {
       const results=[];
       for(let n=0;n<240;n++) {
@@ -35,9 +35,9 @@ with launch(viewport={'width':960,'height':600}) as (_,pg,url):
         }
       }
       drawWorld();await gpuCheckUploads();
-      drawWorld();return {checked:results,cleanCells:GPU.uploadCells};
+      drawWorld();return {checked:results,cleanCells:GPU.uploadCells,workers:simPool.workers.length,active:simPool.activeMax};
     }''')
-    assert min(result['checked'])>1000 and result['cleanCells']==0,result
+    assert min(result['checked'])>1000 and result['cleanCells']==0 and result['workers']>0 and result['active']>0,result
     print('PASS busy ticks, heat, fog, scrolling, both looks: GPU bytes equal full CPU data; clean frame uploads no world cells',result)
     parity=pg.evaluate("""async()=>{
       const results=[];