[Desktop][Feat] Tweak "Fitness trend" zones UI to have label in correct location

[cllns]

Is your feature request related to a problem? Please describe. I was confused about what the labels "Freshness", "Neutral", "Optimal", and "Overload" meant. It wasn't clear to me that they were describing zones (from a min to max), it seemed like they were describing the lines themselves.

Here's a screenshot:

Describe the solution you'd like Putting the labels beneath the lines would be more accurate, since it's describing the zone below the line, not the line itself (which is the threshold between two zones) and it's certainly not the zone above the line, where it's currently located.

Describe alternatives you've considered The labels could be vertical instead, or perhaps be located midpoint within the zone, rather than at the top of the zone. There could also be a line like a bracket } or ] to show it's the entire zone.

Additionally I think "Freshness" could be better labeled as "Fresh", to match the other zone names.