How many speeds does the device actually have? Is it really 100 or are you mapping the percentages to a small number of discrete speeds?
The fan controllers I’ve seen have just a few discrete speeds. The common approach to those is to include the fanSpeed capability that @milandjurovic71 showed in his post above as the visible control on the detail view, and also include the switchLevel capability (but hidden from the detail view) for compatibility with voice assistants that only support percentages. By default, the fanSpeed capability has 4 speeds (Low, Medium, High, Max) but that can be changed by creating a custom device configuration and using a combination of patch and value options in the various sections.
You should also be able to change the “Dimmer” label on the switchLevel capability through the device configuration. @nayelyz has an example here. I’ve been under the impression that changing the labels like that doesn’t play well with translations though, so if this is a product that you’re wanting supported in multiple languages then that might be a consideration. Also, if you’re planning for this device to show with a fan icon, then my observation has been that the fan icon only animates if you use the fanSpeed capability as the dashboard state.