[pan-kot]

Description

See: #278 (comment)

How has this been tested?

Review checklist

The following items are to be evaluated by the author(s) and the reviewer(s).

Correctness

• Changes include appropriate documentation updates.
• Changes are backward-compatible if not indicated, see CONTRIBUTING.md.
• Changes do not include unsupported browser features, see CONTRIBUTING.md.
• Changes were manually tested for accessibility, see accessibility guidelines.

Security

• If the code handles URLs: all URLs are validated through the checkSafeUrl function.

Testing

• Changes are covered with new/existing unit tests?
• Changes are covered with new/existing integration tests?

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[Copilot]

🟢 Approval recommended

No active review issues remain for the zoom-control focus refactor.

No open issues 🎉

What changed in this PR

Refactors focus handling for the internal chart zoom controls, moving it from React effects into the zoom state machine and chart helper.

Changes:

• Adds explicit focus targets for entering, cancelling, and committing zoom selections.
• Registers button references with the chart API and keeps Reset mounted so it can receive focus before state renders.
• Updates control spacing, state-machine tests, and test helpers.

File	Description
src/​core/​styles.scss	Adds spacing between zoom controls.
src/​core/​components/​core-zoom-controls.tsx	Registers focus references and keeps Reset mounted in a hidden wrapper.
src/​core/​chart-zoom/​zoom-state-machine.ts	Replaces operation notifications with explicit focus effects.
src/​core/​chart-zoom/​__tests__/​zoom-state-machine.test.ts	Updates expected effects and adds blur-cancellation coverage.
src/​core/​chart-api/​index.tsx	Exposes zoom-button reference setters.
src/​core/​chart-api/​chart-extra-zoom.ts	Centralizes focus handling for zoom transitions and reset.
src/​core/​__tests__/​common.tsx	Excludes hidden Reset buttons from test lookups.

_{Review effort: Balanced}