fix(dashboard): noCompactor + note edit/preview toggle + widget border

- dashboard-grid: add noCompactor to prevent auto-compaction on drag
- note-widget: edit/preview toggle button (pencil icon), isEditing state,
  hideToolbar in preview mode
- widget-wrapper: border-primary/20 accent border
- dashboard-store: console.error on widget add/remove/layout-save failures

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/web/src/components/dashboard/widgets/widget-wrapper.tsx

@@ -25,7 +25,7 @@ export function WidgetWrapper({ widget, isEditMode, onRemove }: WidgetWrapperPro
 
   return (
     <div
-      className="relative h-full w-full overflow-hidden rounded-lg border bg-card shadow-sm"
+      className="relative h-full w-full overflow-hidden rounded-lg border border-primary/20 bg-card shadow-sm"
       data-widget-id={widget.id}
       role="article"
       aria-label={definition ? t(definition.nameKey) : widget.widgetType}