feat(joint-react): cell focus/blur events, reactive grid, collection setters

[samuelgja]

Description

Several @joint/react <Paper> / graph-API fixes and additions reported

• onCellFocus / onCellBlur events — <Paper> now emits cell:focus / cell:blur when a focusable node (e.g. a tabindex element) inside a cell gains/loses focus. Available both as <Paper> props and via useOnPaperEvents. Implemented by delegating the bubbling focusin / focusout DOM events to .joint-cell (plain focus / blur do not bubble — the same reason React's own onFocus / onBlur use focusin / focusout).

  <Paper onCellFocus={({ id }) => selectCell([id])} />

• Reactive visual grid — changing drawGridSize (and grid options set via the options escape hatch) now redraws the grid. Previously only drawGrid / gridSize triggered a redraw, so drawGridSize updated snapping but left the rendered grid stale.

• removeCells() / resetCells() accept a collection — a JointJS cell collection (e.g. a selection's collection) can be passed directly, without .toArray(). Adds CellCollection / CellRefList types.

  const { removeCells } = useGraph();
  const { collection } = useSelection();
  removeCells(collection); // previously required collection.toArray()

• <Paper> style vs className — verified inline style correctly wins over className, same as a plain HTML div. It already behaved correctly; added a regression test to lock it in.

Motivation and Context

Fixes:

• https://github.com/orgs/clientIO/projects/6/views/13?pane=issue&itemId=210316690
• https://github.com/orgs/clientIO/projects/6/views/13?pane=issue&itemId=210954116
• https://github.com/orgs/clientIO/projects/6/views/13?pane=issue&itemId=210956012
• https://github.com/orgs/clientIO/projects/6/views/13?pane=issue&itemId=210957778

All checks pass locally: typecheck, lint, knip, and Jest (React 19 — 1032 tests, React 18 — 1028 tests). New/updated unit tests cover each change.