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_caps.py

@@ -8,16 +8,18 @@ ensure_playwright()
 from browser import capabilities, consume_gpu_option, launch
 
 consume_gpu_option()
-for case in ['native', 'absent', 'null', 'reject', 'firefox', 'limits']:
+for case in ['native', 'absent', 'null', 'reject', 'firefox', 'limits', 'threads']:
     with launch() as (_, page, url):
         errors = []
         page.on('pageerror', lambda e: errors.append(str(e)))
-        if case != 'native':
+        if case not in ('native', 'threads'):
             gpu = 'undefined' if case == 'absent' else "{requestAdapter: async () => null}"
             if case == 'reject': gpu = "{requestAdapter: async () => {throw new Error('adapter denied')}}"
             if case == 'limits': gpu="{requestAdapter:async()=>({limits:{maxStorageTexturesPerShaderStage:3}})}"
             page.add_init_script(f"Object.defineProperty(navigator, 'gpu', {{value: {gpu}}});")
             page.add_init_script("Object.defineProperty(self, 'crossOriginIsolated', {value: false});")
+        if case == 'threads':
+            page.add_init_script("Object.defineProperty(self, 'crossOriginIsolated', {value: false});")
         if case == 'firefox':
             page.add_init_script("Object.defineProperty(navigator, 'userAgent', {value: 'Firefox/157.0'});")
         page.goto(url)
@@ -26,6 +28,13 @@ for case in ['native', 'absent', 'null', 'reject', 'firefox', 'limits']:
         if case == 'native':
             assert caps['isolated']
             assert page.locator('#cap-notice').is_hidden() == caps['webgpu']
+        elif case == 'threads':
+            assert caps['webgpu'] and not caps['isolated']
+            assert not page.evaluate('canStartGame()')
+            page.evaluate('startNewWorld(424242, 512, 384)')
+            assert not page.evaluate('GAME.running || GAME.loading')
+            assert not page.evaluate('startFromSave({})')
+            assert 'python3 tools/serve.py' in page.inner_text('#cap-notice')
         else:
             assert not caps['webgpu'] and caps['adapterInfo'] is None
             notice = page.inner_text('#cap-notice')