feat: make highlight state controllable for embedding hosts

[vcnainala]

Summary

• Makes NMRium highlight state controllable via optional highlight / onHighlightChange props on <NMRium>, so embedding hosts can drive highlighting (peaks, ranges, signals) without reaching into the private HighlightProvider module.
• HighlightProvider keeps a single source of truth: in controlled mode it renders from value, runs the existing reducer, and reports public state through onChange. Uncontrolled behaviour is unchanged when highlight is omitted. A controlled host must also handle onHighlightChange, otherwise NMRium's own hover/click highlights are not rendered (documented on the prop).
• dispatch keeps a stable identity. Every useHighlight consumer runs an unmount effect keyed on it, so a per-render identity would clear highlights and loop when a host passes an inline callback. The latest state, onChange and mode are read from refs synced in a layout effect (not written during render), and the controlled value is memoized so consumers do not re-render on every provider render.
• Exports NMRiumHighlightState, HighlightEventSource, and emptyHighlightState from the package entry.
• Adds unit tests for the reducer and public/internal state conversion (including consecutive HIDE + UNSET_PERMANENT dispatches), and a controlled-mode demo in TestHighlight. The repo has no React component test setup, so provider behaviour is covered by the demo and by the wrapper's Playwright tests (see below).

Closes #4401

Related: nmrium-react-wrapper#315 (reverted in #316), nmrium-react-wrapper#317 (consumer of this API)

Note for hosts

Hosts that set a highlight from outside should use sourceData: { type: 'UNKNOWN' }. The Delete/Backspace handler deletes the highlighted PEAK / SIGNAL_1D / RANGE source, so claiming one of those would let a keypress delete user data.

Release question

The wrapper is still on React 18 / nmrium@^2.7. The same change is backported on vcnainala:feat/controllable-highlight-v2.8. Would you prefer a 2.x release with the backport, or should the wrapper move to React 19 and NMRium 3?

Performance note

In controlled mode every hover fires onHighlightChange and re-renders the host. For typical embedding (highlight on click, not continuous hover mirroring) this is fine. If a host mirrors hover at scale, the controlled value can be kept in a small store read only by HighlightProvider so the outer provider tree does not re-render.

Test plan

• npx vitest run src/component/highlight (5 tests)
• npm run check-types, eslint, prettier on the changed files
• Wrapper Playwright tests against a packed build of the 2.8 backport: highlight a peak, highlight a signal with its range and peak, and highlight a signal on another nucleus tab (all pass)
• Open the TestHighlight demo, click Highlight A from outside / Clear highlight, and confirm rows update; hover still works
• Load a spectrum in the main app without the new props and confirm peak hover/click highlighting is unchanged