chore: remove unused middleware placeholder

The middleware only passed requests through without modification.
Password lock protection is handled client-side via PasswordLockGuard.

middleware.ts

@@ -1,35 +0,0 @@
-import { NextResponse } from 'next/server';
-import type { NextRequest } from 'next/server';
-
-export async function middleware(request: NextRequest) {
-  const { pathname } = request.nextUrl;
-
-  // Skip middleware for admin routes, API routes, static files, and the lock page itself
-  if (
-    pathname.startsWith('/admin') ||
-    pathname.startsWith('/api') ||
-    pathname.startsWith('/_next') ||
-    pathname.startsWith('/icon.svg') ||
-    pathname === '/lock'
-  ) {
-    return NextResponse.next();
-  }
-
-  // The actual password lock check will be done on the client side
-  // This middleware is kept simple and only used for future extensions
-  return NextResponse.next();
-}
-
-// Configure which routes use this middleware
-export const config = {
-  matcher: [
-    /*
-     * Match all request paths except for the ones starting with:
-     * - api (API routes)
-     * - _next/static (static files)
-     * - _next/image (image optimization files)
-     * - favicon.ico (favicon file)
-     */
-    '/((?!api|_next/static|_next/image|favicon.ico).*)',
-  ],
-};