Fix: Use correct API base URL for client-side fetches

The compare screen and school search modal were not working because
they were fetching from '/api' directly instead of using the
NEXT_PUBLIC_API_URL environment variable that points to the backend.

Fixed client-side fetch calls in:
- ComparisonView: Fetch comparison data with correct API URL
- SchoolSearchModal: Search schools with correct API URL

This ensures client-side requests go to the FastAPI backend at
the configured URL (e.g., http://localhost:8000/api) rather than
trying to hit non-existent Next.js API routes.

Fixes comparison screen showing no data when schools are selected.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

nextjs-app/components/SchoolSearchModal.tsx

@@ -36,7 +36,8 @@ export function SchoolSearchModal({ isOpen, onClose }: SchoolSearchModalProps) {
 
         setIsSearching(true);
         try {
-          const response = await fetch(`/api/schools?search=${encodeURIComponent(term)}&page_size=10`);
+          const apiBaseUrl = process.env.NEXT_PUBLIC_API_URL || '/api';
+          const response = await fetch(`${apiBaseUrl}/schools?search=${encodeURIComponent(term)}&page_size=10`);
           const data = await response.json();
           setResults(data.schools || []);
           setHasSearched(true);