fix: activate New row button via keyboard (Enter/Space)

The New row control is a role=button div with no keydown handler, so Enter/Space never triggered it. It also lives inside the grid element, whose native keydown listener caught the Enter and ran cell navigation against the previously focused cell.

Add Enter/Space activation to the button, and make the grid keyboard handler ignore keydowns that originate from a focusable child rather than the grid element itself, so in-grid controls handle their own keys.

apps/client/src/ee/base/components/grid/add-row-button.tsx

@@ -16,6 +16,12 @@ export const AddRowButton = memo(function AddRowButton({
     <div
       className={classes.addRowButton}
       onClick={onClick}
+      onKeyDown={(e) => {
+        if (e.key === "Enter" || e.key === " ") {
+          e.preventDefault();
+          onClick?.();
+        }
+      }}
       role="button"
       tabIndex={0}
     >

apps/client/src/ee/base/hooks/use-grid-keyboard-nav.ts

@@ -166,6 +166,8 @@ export function useGridKeyboardNav({
         return;
       }
 
+      if (e.target !== containerRef.current) return;
+
       if (isTextEntry(document.activeElement)) return;
 
       if (e.key === "Escape") {
@@ -263,6 +265,7 @@ export function useGridKeyboardNav({
       }
     },
     [
+      containerRef,
       editingCell,
       focusedCell,
       getRowIds,