Heart rate chart redesign

[tituscmd]

Hey all!

This PR reworks the heart rate chart to more closely match the style of Apple Health.

Instead of the previous line/area chart, it now uses a range bar chart that groups readings by the hour, showing the min/max range as a darker bar and the average of that hour as a brighter dot overlaid on top. The header still shows the BPM range and date for the day you're currently viewing, and now fluidly updates when you navigate to a different day.

Since smooth horizontal scrolling requires iOS 17+, I went with a chevron-based day navigation approach instead to keep things compatible with iOS 16. The chart fetches up to a week of data, using the existing weekPredicate in ChartManager, instead of the previously used dayPredicate. Only the data from the current week is fetched, not the last 7 days, similar to how the step chart operates.

The Y axis scales dynamically to the visible data rather than being hardcoded, which I think makes it a lot more readable especially when readings are close together.

Hope you like it 🙂

[liamcharger]

Another thing, you can remove "Apple Charts with date range selection" from the readme

[liamcharger]

Ok so I just pushed a rather large commit. I cleaned up a couple things:

• The fixed and scrollable charts were completely independent of each other when they could use some of the same components/variables
• There was some unnecessary listeners that I replaced with computed properties (updateDisplayed, updateYScale)
• Oh I also changed the position of the chevrons on the fixed chart

One of the main things to keep in mind is to keep the code as small as possible; I saw a few components that could be shrunk or extracted. I'll publish some best practices at some point you can glance at :)

Also feel free to let me know if I broke anything :)))

[liamcharger]

Thanks for the fixes!