VRC 470: one-time DHW load — solved by writing HwcOPMode=load (see ebusd-configuration#128)

[amiel-35]

Update, same day: withdrawn — the answer was already in john30/ebusd-configuration#128 (2023 comments): on the VRC 470, writing HwcOPMode = load (6) with a write definition for register 4200 starts the one-time DHW load. Verified today on F4700 SW 0114 with micro-ebusd on a C6 (regulator re-reads load, opens its DHW load window, auto cancels). A PR making HwcOPMode writable in 15.470.tsp will follow.