refactor(admin-web): remove dead local components — already using @bytelyst/dashboard-components

Removed unused local copies that were superseded by shared package imports:
- EmptyState.tsx (dead — no imports found)
- LoadingSpinner.tsx (dead — no imports found)
- PageHeader.tsx (dead — no imports found)

Dashboard already consumes NotFoundPage from @bytelyst/dashboard-components.

dashboards/admin-web/src/components/EmptyState.tsx

@@ -1,27 +0,0 @@
-import type { ReactNode } from 'react';
-import { Button } from './ui/button';
-
-interface EmptyStateProps {
-  icon?: ReactNode;
-  title: string;
-  description: string;
-  action?: {
-    label: string;
-    onClick: () => void;
-  };
-}
-
-export function EmptyState({ icon, title, description, action }: EmptyStateProps): ReactNode {
-  return (
-    <div className="flex flex-col items-center justify-center min-h-[300px] p-8 text-center">
-      {icon && (
-        <div className="w-16 h-16 rounded-full bg-muted flex items-center justify-center mb-4">
-          {icon}
-        </div>
-      )}
-      <h3 className="text-lg font-medium mb-2">{title}</h3>
-      <p className="text-muted-foreground max-w-sm mb-6">{description}</p>
-      {action && <Button onClick={action.onClick}>{action.label}</Button>}
-    </div>
-  );
-}

dashboards/admin-web/src/components/LoadingSpinner.tsx

@@ -1,37 +0,0 @@
-interface LoadingSpinnerProps {
-  size?: 'sm' | 'md' | 'lg';
-  className?: string;
-}
-
-export function LoadingSpinner({ size = 'md', className = '' }: LoadingSpinnerProps) {
-  const sizeClasses = {
-    sm: 'w-4 h-4',
-    md: 'w-8 h-8',
-    lg: 'w-12 h-12',
-  };
-
-  return (
-    <div className={`${sizeClasses[size]} ${className}`}>
-      <svg
-        className="animate-spin text-primary"
-        xmlns="http://www.w3.org/2000/svg"
-        fill="none"
-        viewBox="0 0 24 24"
-      >
-        <circle
-          className="opacity-25"
-          cx="12"
-          cy="12"
-          r="10"
-          stroke="currentColor"
-          strokeWidth="4"
-        />
-        <path
-          className="opacity-75"
-          fill="currentColor"
-          d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm2 5.291A7.962 7.962 0 014 12H0c0 3.042 1.135 5.824 3 7.938l3-2.647z"
-        />
-      </svg>
-    </div>
-  );
-}

dashboards/admin-web/src/components/PageHeader.tsx

@@ -1,34 +0,0 @@
-import type { ReactNode } from 'react';
-
-interface PageHeaderProps {
-  title: string;
-  breadcrumbs?: Array<{ label: string; href?: string }>;
-  actions?: ReactNode;
-}
-
-export function PageHeader({ title, breadcrumbs, actions }: PageHeaderProps): ReactNode {
-  return (
-    <div className="flex items-center justify-between mb-6">
-      <div>
-        {breadcrumbs && breadcrumbs.length > 0 && (
-          <nav className="flex items-center space-x-2 text-sm text-muted-foreground mb-2">
-            {breadcrumbs.map((crumb, index) => (
-              <span key={index} className="flex items-center">
-                {index > 0 && <span className="mx-2">/</span>}
-                {crumb.href ? (
-                  <a href={crumb.href} className="hover:text-foreground">
-                    {crumb.label}
-                  </a>
-                ) : (
-                  <span>{crumb.label}</span>
-                )}
-              </span>
-            ))}
-          </nav>
-        )}
-        <h1 className="text-2xl font-bold">{title}</h1>
-      </div>
-      {actions && <div className="flex items-center space-x-3">{actions}</div>}
-    </div>
-  );
-}