fix(Widgets): release owned picking resources on deletion

[PaulHax]

Context

vtkWidgetManager owns its per-view widgets and its hardware selector, and delete() left both alive. The selector holds a full-window framebuffer, color texture and depth renderbuffer per view; a focused widget keeps an animation request on the interactor that only losing focus cancels, so a deleted manager could pin the requestAnimationFrame loop forever.

Results

Deleting a widget manager, including mid-capture or while a widget has focus, returns the live WebGL object count to baseline, stops the focused widget's animation request, and no longer lets a stale capture serve selections. setRenderer frees the selector built for the previous wiring instead of leaking it.

Changes

• vtkWidgetManager.delete() releases focus, removes the view widgets, and deletes the selector once any in-flight capture settles. Losing focus re-enables picking, so deletion also suppresses the capture that renderWidgets would otherwise start on the way out.
• vtkOpenGLHardwareSelector chains releaseGraphicsResources() into delete() so its framebuffer goes with it.
• setRenderer drops the captured buffers and in-flight capture belonging to the previous wiring; a capture that settles after the manager was deleted or re-targeted no longer publishes stale buffers (previously an in-flight capture for renderer A could serve selections after a switch to renderer B). setRenderer with the same renderer intentionally remains a full re-wire: it re-reads camera/interactor/view off the renderer and rebuilds the selector.
• getSelectedDataForXY handles a capture that produced nothing to select against (selector bailed on a half-torn-down view) instead of throwing from the mousemove chain.
• Documentation and TypeScript definitions were updated to match those changes

PR and Code Checklist

• semantic-release commit messages
• Run npm run reformat to have correctly formatted code