elijah629/jamRF ? reverse-engineered prompt

Build me a Flipper Zero app that lets me jam Sub GHz RF on a selected frequency.

I want a simple screen where I can use the left and right buttons to change the frequency, then press Ok to start jamming. If the chosen frequency is not allowed on the device, it should not start and should show a clear message. If an external CC1101 is available and configured, use that automatically, otherwise use the built in antenna.

Please keep it lightweight and easy to use, with a clear warning about safety and legal use, since this can damage the radio if run too long. The app should feel like a compact utility for the Flipper Zero, not a big complicated interface.

If you need to check any current Flipper Zero docs or APIs, look them up online first and then wire it up cleanly so it builds and runs.