Page.navigate omits loaderId for same-document navigations (#fragment,
History API), and Chrome emits no new load/DOMContentLoaded lifecycle events
for them — the navigation is already committed when Page.navigate returns.
The stale-event timestamp guard would otherwise reject all buffered events
and burn the full readiness timeout.
Short-circuit when loaderId is absent, and simplify the stale-event guard
(the no-navigation-id case can no longer reach it). Regression test drains
the previous load's trailing networkIdle first so a stale event can't
accidentally satisfy the wait.
Saurav Panda
b4b6868232