Add minimal TypeScript stub for @sentry/nextjs module

Co-authored-by: rahul.chhabria <[email protected]>

Author: cursoragent

src/@types/sentry__nextjs.d.ts

@@ -0,0 +1,5 @@
+// Minimal stub for @sentry/nextjs so that TypeScript can resolve the module
+// during local development and preview builds. The real package ships its own
+// types, but CI environments without full Node resolution may still need this.
+
+declare module '@sentry/nextjs';