[charts-pro] Auto-select range button matching current zoom

[JCQuintas]

Summary

• Range buttons in ChartsToolbarPro now mark themselves as selected whenever the current zoom matches their computed range, so initialZoom (or controlled zoomData) landing on a button's range highlights it on first render without user interaction.
• Since selection is now derived purely from the live zoom range, the internal activeRangeButtonKey state, setActiveRangeButtonKey instance method, and selectorChartActiveRangeButtonKey selector have been removed. This also drops the manual resets previously needed on every pan/wheel/zoom.
• Minor docs demo fix: added <span> wrappers around the zoom-in / zoom-out triggers in ChartsToolbarCustomToolbar so Tooltip no longer receives a disabled <button> as a direct child (was producing a console warning).
• New docs demo ChartsToolbarRangeButtonsInitialSelection illustrates the behavior.

[code-infra-dashboard]

Bundle size

Bundle	Parsed size	Gzip size
@mui/x-data-grid	0B(0.00%)	0B(0.00%)
@mui/x-data-grid-pro	0B(0.00%)	0B(0.00%)
@mui/x-data-grid-premium	0B(0.00%)	0B(0.00%)
@mui/x-charts	0B(0.00%)	0B(0.00%)
@mui/x-charts-pro	▼-66B(-0.01%)	🔺+18B(+0.01%)
@mui/x-charts-premium	▼-66B(-0.01%)	🔺+14B(+0.01%)
@mui/x-date-pickers	0B(0.00%)	0B(0.00%)
@mui/x-date-pickers-pro	0B(0.00%)	0B(0.00%)
@mui/x-tree-view	0B(0.00%)	0B(0.00%)
@mui/x-tree-view-pro	0B(0.00%)	0B(0.00%)

Details of bundle changes

Deploy preview

• docs/data/charts/toolbar/toolbar.md

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[codspeed-hq]

Merging this PR will not alter performance

✅ 14 untouched benchmarks

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_{Comparing JCQuintas:intial-range-button-selected (b463566) with master (3bac9bb)¹}

Footnotes

1. No successful run was found on master (7ffafb3) during the generation of this report, so 3bac9bb was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩