Forbid a "direct send" when a jar is "swept" or vice versa

to not hurt themselves, the user shouldn't be able to sweep a jar AND combine it with a "direct send" aka deactivated coinjoin send.

- so either its "I want to sweep", the user clicks on sweep, then the toggle under options stays **ON** but gets "deactivated" to toggle off
- or its "I want to send a direct send", so the user turns off the toggle under options but then the "sweep" button gets also deactivated on the amount input

it would be also good to have a mouse overlay that's hints why the toggle or sweep button got deactivated:
- "This function is deactivated because direct send was activated."
- "This function is deactivated because sweep wallet was activated."

(this routine has nothing todo with the overall wallet "sweep" function from the header menu)

The issue does not name files or tests; start by locating the amount input, sweep button, and direct-send toggle in the frontend. Verify that enabling either option disables the other and that each disabled control explains why it is unavailable, then test both interaction paths manually.

Written by the indexing model from the issue text.