How do linear actuators for flight controls work in fighter jets?
The working principle is surprisingly similar between the RC as you've described and most actuator powered aircraft. The linear actuator extends/retracts a pushrod, which is connected to a horn attached to the pivot point on the control surface.
Below is the zoomed-in picture from the OP. I've taken the liberty of highlighting the two rudder actuators and the left stabilator actuator. The one attached to the stabilator is the most revealing: the pushrod essentially connects to a horn, which translates the linear motion to a rotational one.

Ref: https://conceptbunny.com/lockheed-martin-f-22-raptor/
Due to aerodynamic and stealth reasons, this mechanism is hidden under a smooth fairing for the F-22. But for other airplanes, you can see small blisters under their control surfaces that fair the actuator. Below is a picture of the Boeing 787 aileron. The blisters have been highlighted.

Ref: https://commons.wikimedia.org/wiki/File:Low-speed_aileron_of_Boeing_787.jpg
The linear actuator itself is almost always energized via hydraulic fluid, whether it comes from a central hydraulic system or an self-contained hydraulic systems (EHA). The following diagram illustrates the working principle:

Ref: https://www.machinedesign.com/mechanical-motion-systems/linear-motion/article/21832047/whats-the-difference-between-pneumatic-hydraulic-and-electrical-actuators