What this does: loads the same
cohort_graph.json from Step 2/3 and re-indexes it around a chosen
anchor instead of a chosen patient. Three lenses, same underlying graph, same data, no rebuild:
Disease-centered (anchor = a Diagnosis node — "given patients diagnosed with X, what walked in and what did we do?"),
Intervention-centered (anchor = an Intervention node — "when we deploy Y, who receives it and how do outcomes vary?"),
and Disease + Intervention combo (anchor = the composite hyper-node — "when Diagnosis A patients receive Intervention B, why do outcomes diverge?").
Selecting a lens re-clusters the same patients around the new anchor; it never re-derives or special-cases T1D vs. T2D in code.
No file loaded yet — use the cohort_graph.json exported from Step 2 (same file works for Step 3 and Step 4).