feat(agents): implement grid/list view toggle and enhance filters

- Added grid and list view modes to AgentTypeList with user preference management.
- Enhanced filtering with category selection alongside existing search and status filters.
- Updated AgentTypeDetail with category badges and improved layout.
- Added unit tests for grid/list views and category filtering in AgentTypeList.
- Introduced `@radix-ui/react-toggle-group` for view mode toggle in AgentTypeList.

frontend/src/components/ui/toggle-group.tsx

@@ -0,0 +1,93 @@
+'use client';
+
+import * as React from 'react';
+import * as ToggleGroupPrimitive from '@radix-ui/react-toggle-group';
+import { type VariantProps, cva } from 'class-variance-authority';
+
+import { cn } from '@/lib/utils';
+
+const toggleGroupVariants = cva(
+  'inline-flex items-center justify-center rounded-md border bg-transparent',
+  {
+    variants: {
+      variant: {
+        default: 'bg-transparent',
+        outline: 'border border-input',
+      },
+    },
+    defaultVariants: {
+      variant: 'outline',
+    },
+  }
+);
+
+const toggleGroupItemVariants = cva(
+  'inline-flex items-center justify-center whitespace-nowrap text-sm font-medium ring-offset-background transition-all focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 disabled:pointer-events-none disabled:opacity-50 data-[state=on]:bg-accent data-[state=on]:text-accent-foreground',
+  {
+    variants: {
+      variant: {
+        default: 'bg-transparent hover:bg-muted hover:text-muted-foreground',
+        outline: 'bg-transparent hover:bg-accent hover:text-accent-foreground',
+      },
+      size: {
+        default: 'h-10 px-3',
+        sm: 'h-9 px-2.5',
+        lg: 'h-11 px-5',
+      },
+    },
+    defaultVariants: {
+      variant: 'default',
+      size: 'default',
+    },
+  }
+);
+
+const ToggleGroupContext = React.createContext<VariantProps<typeof toggleGroupItemVariants>>({
+  size: 'default',
+  variant: 'default',
+});
+
+const ToggleGroup = React.forwardRef<
+  React.ElementRef<typeof ToggleGroupPrimitive.Root>,
+  React.ComponentPropsWithoutRef<typeof ToggleGroupPrimitive.Root> &
+    VariantProps<typeof toggleGroupVariants> &
+    VariantProps<typeof toggleGroupItemVariants>
+>(({ className, variant, size, children, ...props }, ref) => (
+  <ToggleGroupPrimitive.Root
+    ref={ref}
+    className={cn(toggleGroupVariants({ variant }), className)}
+    {...props}
+  >
+    <ToggleGroupContext.Provider value={{ variant, size }}>{children}</ToggleGroupContext.Provider>
+  </ToggleGroupPrimitive.Root>
+));
+
+ToggleGroup.displayName = ToggleGroupPrimitive.Root.displayName;
+
+const ToggleGroupItem = React.forwardRef<
+  React.ElementRef<typeof ToggleGroupPrimitive.Item>,
+  React.ComponentPropsWithoutRef<typeof ToggleGroupPrimitive.Item> &
+    VariantProps<typeof toggleGroupItemVariants>
+>(({ className, children, variant, size, ...props }, ref) => {
+  const context = React.useContext(ToggleGroupContext);
+
+  return (
+    <ToggleGroupPrimitive.Item
+      ref={ref}
+      className={cn(
+        toggleGroupItemVariants({
+          variant: context.variant || variant,
+          size: context.size || size,
+        }),
+        className
+      )}
+      {...props}
+    >
+      {children}
+    </ToggleGroupPrimitive.Item>
+  );
+});
+
+ToggleGroupItem.displayName = ToggleGroupPrimitive.Item.displayName;
+
+export { ToggleGroup, ToggleGroupItem };