Problem: Keyboard navigation in the grid is broken. Selecting a row or cell no longer triggers focus on the grid body wrapper, preventing KeyNavigation from capturing arrow key events. Additionally, focusing the body wrapper manually causes a layout shift where the header toolbar is scrolled out of view.

Scope:

1. Focus Restoration: Ensure GridBody receives focus on row/cell clicks.
2. Layout Stability: Implement preventScroll support for focus() to stop the browser from scrolling the parent container.

Changes Required:

• src/main/DomAccess.mjs: Update focus to support preventScroll.
• src/component/Base.mjs: Update focus signature to pass preventScroll.
• src/grid/Body.mjs: Call this.focus(this.vdom.id, false, true) in onRowClick.