Lamp control with dimmer actuator and wireless switch

Do you then still need a bridge or something similar for Hue?

Eltako or EnOcean has battery-free wireless switches.

The switches can certainly have batteries.
Is there also something like that for [smart Home]?
So controllable via app.

Smart has nothing to do with [App].

What is smart in your eyes?

Remote controlled is rather the opposite of smart... you first have to look for your phone to turn on the light ;) "Smart" means that you don’t have to worry about it because it adjusts itself as optimally as possible through sensors (PM) and some situation-dependent programming.