Check initialization ordering before locating funnel drop-off

When reconstructing a browser funnel from an opened event, check whether step-entry events are emitted before that anchor during initialization. A strict event-time join starting at opened can erase the initial screen and falsely classify resumed visits as having no stage activity. Use a bounded diagnostic lookback or a shared visit identifier to recover the initial stage, while keeping outcome follow-up anchored to the original exposure. Do not count the lookback as new progress or infer that a recorded internal stage was visibly displayed; an introductory overlay may still be covering it. Applies when: separately initialized browser telemetry streams feed flow-level abandonment analysis. Keywords: PostHog funnel initialization ordering opened event stage resume attribution