Screen stare remover

### Description of the new feature / enhancement

It fixes you focal length as per user input.
Input can be by mouse, mousekey or cursor key.
User must click or tap if eye/s are better.

### Scenario when this would be used?

Dirty glasses, dirty screen, dirty table, bipolar disorder, head injury, eye surgery, glaucoma, floaters

### Supporting information

Neuralvisualiser or Neuravisualiser (cant remember now) and other similar websites may simplify app developement

The issue names no PowerToys utility, file, entry point, or test. Start by clarifying the intended focal-length behavior, supported input methods, visual feedback, and scope of the proposed medical use cases. Done would require an agreed design, an identified utility location, and clear acceptance criteria for mouse, mouse-key, cursor-key, and click/tap interactions.

Written by the indexing model from the issue text.