refactor(aria/grid): Add accessors for pattern properties

Author: adolgachev

src/aria/grid/grid.ts

@@ -77,6 +77,21 @@ export class Grid {
   /** The wrapping behavior for keyboard navigation along the column axis. */
   readonly colWrap = input<'continuous' | 'loop' | 'nowrap'>('loop');
 
+  /** Whether multiple cells in the grid can be selected. */
+  readonly multi = input(false, {transform: booleanAttribute});
+
+  /** The selection strategy used by the grid. */
+  readonly selectionMode = input<'follow' | 'explicit'>('follow');
+
+  /** Whether enable range selections (with modifier keys or dragging). */
+  readonly enableRangeSelection = input(false, {transform: booleanAttribute});
+
+  /** Whether the user is currently dragging to select a range of cells. */
+  readonly dragging = computed(() => this._pattern.dragging());
+
+  /** Whether the focus is in the grid. */
+  readonly isFocused = computed(() => this._pattern.isFocused());
+
   /** The UI pattern for the grid. */
   readonly _pattern = new GridPattern({
     ...this,