Vaillant sensoCOMFORT VRC700 ventilation

Problem On VRC700 controllers (e.g. sensoCOMFORT) `climate.set_fan_mode` fails for the ventilation entity for every mode except `auto`. Each call returns a 500 in Home Assistant because the myVAILLANT API rejects the request: [code] ### Root cause `async_set_fan_mode` resolves the operation mode with `[k for k, v in self.fan_mode_map.items() if v == fan_mode][0]`. The VRC700 `fan_mode_map` maps both `NORMAL → FAN_ON` and `DAY → FAN_ON` (and `REDUCED → FAN_LOW`, `SET_BACK → FAN_LOW`). `[0]` therefore picks `NORMAL` / `REDUCED`, which the VRC700 ventilation endpoint does not accept. I verified …

Excerpt saved from GitHub on 2026-10-23.