What the doctor will see — built by the doctor's own payload function.

§2.3. The load-bearing decision is that this calls _blind_task, the exact function the serve path calls, rather than assembling its own view of the case. A preview that reimplemented the payload would be a SECOND definition of "what a physician may see", and the first time the two drifted the admin screen would show a future the portal correctly hides — which is not a cosmetic difference. A screenshot of encounter 6 pasted into a Slack thread leaks the answer to decision 5 exactly as thoroughly as serving it would, and just as permanently.

For a longitudinal point the truncation is already baked into the stored case (build_encounter_case writes the visible window, not the whole chart), so reusing the serve payload inherits it for free. A test asserts the preview carries no offset past the decision point, because "inherits it for free" is the kind of claim that stops being true after an innocent refactor.