fix(chart) :: align stacked series on their X values

[81reap]

Addresses #1362

Motivation

• ApexCharts stacks series by point order, not by x value, so a series missing a point is squashed on top of the wrong one.
• The chart then incorrect data and totals without any warning.
• SQLPage already aligned series on their x values, but only for bar charts on a text axis.

Description

• Order the merged axis by what the series already agree on, falling back to ascending order where they diverge, so one unsorted series cannot reorder the chart.
• Align whenever a chart is stacked, on top of the existing bar-on-a-text-axis case.
• Add tests/js/, run by Node's test runner from npm test, since this logic is worth testing without a browser.
• Document the behaviour on the stacked parameter, and add the stacked area example from stacked area graphs / stacked line graphs #1362.
• Add a changelog entry.

Testing

• 13 unit tests cover the merge order, dates compared by value, a null treated as missing, and the input left unmutated.
• The browser suite passes 33 tests, five of them new, including a stacked area chart whose series do not share their x values.
• npm test checks 41 files and reports nothing.
• no console errors on card page fails for the reason described in fix(biome.js) :: fix remaining lint issues #1366, on this branch and on the unmodified base alike.

---

GitHub cannot base a pull request on a branch that lives in a fork, so all eight target main and each one carries the commits of those above it. Review and merge them in order:

1. fix(biome.js) :: fix remaining lint issues #1366 :: fix(biome.js) :: fix remaining lint issues
2. fix(modal) :: give modal component an accessible name #1367 :: fix(modal) :: give modal component an accessible name
3. fix(map) :: ignore map coordinates that are not a pair of numbers #1368 :: fix(map) :: ignore map coordinates that are not a pair of numbers
4. feat(chart) :: render column charts as bar charts #1369 :: feat(chart) :: render column charts as bar charts
5. fix(chart) :: align stacked series on their X values #1370 :: fix(chart) :: align stacked series on their X values ← this PR
6. fix(chart) :: line series up on a category axis for every chart type #1371 :: fix(chart) :: line series up on a category axis for every chart type
7. fix(npm) :: install dependencies only once at root level #1372 :: fix(npm) :: install dependencies only once at root level
8. feat(typescript) :: typecheck browser JavaScript in CI #1373 :: feat(typescript) :: typecheck browser JavaScript in CI

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[lovasoa]

The align_categories function we have is the result of multiple iterations on user feedback. I'm not confident merging this without a good argument that this is not going to break people's existing charts.

What I'd need is a clear description of the difference between the old and the new algorithms and why you think this difference is not going to break any reasonable existing chart.

[81reap]

I really don't have context on the history of how this function came to be, so I had Claude look into old issues to find out. I've added those examples as tests so that we can check for regression. lmk if you think I may have missed any issues.

commit	issue	rule it added
5ff3b50	#727	every series gets a point in every category, and skipped categories count as 0
ca00eaa	#930	a chart with one series keeps the order the query returned
ee156d9	#951	categories the series don't share are sorted by name
32a875d	—	same rules, faster loop

But to put it in words :: the algorithm is functionally the same; the new part only adds stacked line, area and bar charts whose x is a date or a number.

// before
} else if (categories && chart_type === "bar" && series.length > 1)
// after
} else if (series.length > 1 && (is_stacked || (categories && chart_type === "bar")))

Other small changes:

• Points keep their z value instead of being rebuilt as {x, y}, so nothing visible changes but we do less work. This also means SQLPage should now be able to handle 3D charts but I think that's better scoped for another PR to properly test and fix any other straggling issues in the codebase.
• Two equal dates now match. The old code only ran on strings so it wasn't caught before.

@lovasoa lmk if that makes sense :)

[lovasoa]

Thank you !

[81reap]

no prob! thanks for the feedback and review :)