fix(ui): correct Y-axis tick precision on Docker memory chart

[svenvg93]

📃 Description

Fix incorrect Y-axis tick label precision on the Docker/Podman Memory Usage chart. Because container memory is stored in MB, the raw value (val) was always ≥ 10, so toFixedFloat was always called with 0 decimal places. This caused values in the 1–10 GB range to be rounded to the nearest whole GB, producing duplicate and misleading tick labels (e.g. both 1.2 GB and 1.5 GB displaying as "1 GB", and 1.8 GB displaying as "2 GB"), making the axis appear non-linear.

Also corrects a wrong JSDoc comment on the container Stats type — memory is in MB, not GB.

closes #2026

🪵 Changelog

🔧 Fixed

• Docker/Podman Memory Usage chart: Y-axis tick labels for values in the 1–10 GB range now show one decimal place (e.g. "1.8 GB") instead of rounding to the nearest whole GB, preventing duplicate or misleading tick labels