fix: serve uploaded images via /api/media/[name] to avoid Next.js static 404

src/app/api/media/route.ts

@@ -15,7 +15,7 @@ export async function GET() {
     .filter((f) => /\.(png|jpg|jpeg|gif|webp|svg|bmp)$/i.test(f))
     .map((f) => ({
       name: f,
-      url: `/${MEDIA_DIR}/${f}`,
+      url: `/api/media/${f}`,
     }))
     .sort((a, b) => a.name.localeCompare(b.name));