test(web): pin the startup auto-selection hero in the assembled app

Holds the session.history response at the browser's network boundary so
the auto-selected open is observable, then asserts the visible frame and
the recorded phase timeline. Registered host-plane like the other
scaffold-booting e2e files (host include + client project exclude).

tsconfig.host.json

@@ -35,6 +35,7 @@
     "apps/web/tests/skill-invocation-policy.e2e.ts",
     "apps/web/tests/permission-policy-context.e2e.ts",
     "apps/web/tests/access-confirmation.e2e.ts",
+    "apps/web/tests/startup-auto-selection.e2e.ts",
     "apps/cli/tests/**/*.ts",
     "examples/*/src/**/*.ts",
     "examples/*/start.ts",