Improve admin access and navigation links for superadmins

Update `App.tsx` to grant superadmin access to the admin dashboard and refactor navigation links to use `Link` component from `wouter`. Modify `DatabaseStorage` in `server/storage.ts` to update user records based on email instead of ID.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 069d4324-6c40-4355-955e-c714a50de1ea
Replit-Commit-Checkpoint-Type: intermediate_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/3df548ff-50ae-432f-9be4-25d34eccc983/069d4324-6c40-4355-955e-c714a50de1ea/bVdKIaU

client/src/App.tsx

@@ -26,7 +26,7 @@ function Router() {
           <Route path="/media/:slug" component={MediaOutlet} />
           <Route path="/articles/:slug" component={Article} />
           <Route path="/auctions" component={Auctions} />
-          {user?.role === 'admin' && (
+          {(user?.role === 'admin' || user?.role === 'superadmin') && (
             <Route path="/admin" component={AdminDashboard} />
           )}
           {user?.role === 'superadmin' && (