Revert

For each existing unit: the first day it recorded any dispatch, and the first day its output sustained at or above 90% of nameplate capacity, from actual dispatch history, not the ISP forecast dates below.

Per-unit commissioning date, capacity and status by region, fuel and DUID, plus each unit's ramp-to-nameplate dates and retirement date where on file. Forecast rows (committed / anticipated) are dated from the ISP 2026 assumptions.