Add admin dashboard and Replit authentication integration

Integrates Replit authentication using OpenID Connect, adds an admin dashboard route with video management and thumbnail upload capabilities, and updates dependencies.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 890577b1-c154-40a4-a177-a0c6d55320c3
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/8cc42625-c1f5-4e43-99bd-77f2c4dedee2/890577b1-c154-40a4-a177-a0c6d55320c3/1jMBtLj

client/src/components/loading-spinner.tsx

@@ -4,7 +4,7 @@ interface LoadingSpinnerProps {
   className?: string;
 }
 
-export default function LoadingSpinner({ size = 'md', text = 'Loading...', className = '' }: LoadingSpinnerProps) {
+export function LoadingSpinner({ size = 'md', text = 'Loading...', className = '' }: LoadingSpinnerProps) {
   const sizeClasses = {
     sm: 'w-6 h-6',
     md: 'w-10 h-10', 
@@ -25,4 +25,6 @@ export default function LoadingSpinner({ size = 'md', text = 'Loading...', class
       <div className={`text-white ${textSizeClasses[size]} font-medium`}>{text}</div>
     </div>
   );
-}
+}
+
+export default LoadingSpinner;