Regenerate a claim's end-of-year report (the Review-tab narrative answers).

Re-runs the same AI writer that produced the report initially, against the current tracking structure — so changes like merging two projects on the tracking page are reflected. Unlike the discovery /regenerate endpoint this is non-destructive to tracking data: it only reconciles answer instances orphaned by merges, then regenerates all AI-answerable questions in place (regenerate=True), overwriting existing answers.