Served with isolation headers; start-screen capability notices; tests on the real GPU (t88 phase 1)

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

tools/playthrough.py

@@ -2,16 +2,14 @@
 import sys, time, pathlib
 sys.path.insert(0, str(pathlib.Path(__file__).resolve().parent))
 from use_venv import ensure_playwright; ensure_playwright()
-from playwright.sync_api import sync_playwright
+from browser import launch, consume_gpu_option
+consume_gpu_option()
 
 root = pathlib.Path(__file__).resolve().parent.parent
 out = pathlib.Path(sys.argv[1] if len(sys.argv) > 1 else root / 'shots' / 'playthrough')
 out.mkdir(parents=True, exist_ok=True)
-url = (root / 'dist' / 'index.html').as_uri()
 
-with sync_playwright() as p:
-    b = p.chromium.launch(args=['--autoplay-policy=no-user-gesture-required'])
-    pg = b.new_page(viewport={'width': 1440, 'height': 860})
+with launch(viewport={'width': 1440, 'height': 860}, args=['--autoplay-policy=no-user-gesture-required']) as (b, pg, url):
     logs = []
     pg.on('console', lambda m: logs.append(f'{m.type}: {m.text}'))
     pg.on('pageerror', lambda e: logs.append(f'PAGEERROR: {e}'))