Profiler: real-GPU breakdown by zoom, look and scene, with a baseline (t88 phase 0)

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

tools/server.py

@@ -0,0 +1,33 @@
+"""Serve dist/ with isolation headers; isolated_server() owns a free-port background server."""
+from contextlib import contextmanager
+from http.server import SimpleHTTPRequestHandler, ThreadingHTTPServer
+from pathlib import Path
+from threading import Thread
+
+DIST = Path(__file__).resolve().parent.parent / 'dist'
+
+
+class Handler(SimpleHTTPRequestHandler):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, directory=str(DIST), **kwargs)
+
+    def end_headers(self):
+        self.send_header('Cache-Control', 'no-store')
+        self.send_header('Cross-Origin-Opener-Policy', 'same-origin')
+        self.send_header('Cross-Origin-Embedder-Policy', 'require-corp')
+        super().end_headers()
+
+    def log_message(self, format, *args):
+        pass
+
+
+@contextmanager
+def isolated_server():
+    with ThreadingHTTPServer(('127.0.0.1', 0), Handler) as server:
+        thread = Thread(target=server.serve_forever, daemon=True)
+        thread.start()
+        try:
+            yield f'http://127.0.0.1:{server.server_port}'
+        finally:
+            server.shutdown()
+            thread.join()