Customizable data smoothing

There is a new checkbox: Customize data smoothing (defaults are already applied — use only for edge cases). Use it when your metrics look jumpy and you want more control over smoothness, spike reduction, and elevation smoothing.

Defaults are enough in most cases. Turn this on only when the data still looks too bumpy.

• Typical use case: runners — running GPS is often very bumpy. Try Medium, or High in the worst cases.
• Be careful with High — short bursts of real speed can look lower than they were.
• Elevation smoothing — another option in the same panel. Use when your grade jumps often — common for runners. Skip if grade is already stable.