Validate / fix - display precision interactions

## 🐜 Bug description

Might be adjacent to #34

The display precision used to do weird things when adjusted from the UI. The typescript side would say something like "this sensor is 1 billion bytes", and on the UI the user says "I want GB"

This at least used to case some weird desync situations where both sides were not in alignment about units / their quantity. Was not clear if it's a Python issue, or TS was also incorrect. I'm inclined to think python only, so filing issue here

It's plausible this issue is no longer present, it was not an explicit test scenario after the recent rebuild

Start by reproducing the display-precision interaction described in the issue, checking whether the Python and TypeScript sides disagree about units or quantities after the UI changes them. Compare the current behavior with the recent rebuild and add an explicit test scenario if the mismatch still occurs. Done means the UI and backend remain aligned about the selected unit and quantity.

Written by the indexing model from the issue text.