fix(entraid): correct package entry point structure

Add root index.ts to properly expose package exports through `@redis/entraid`
rather than requiring users to import through `@redis/entraid/dist/lib`.
This maintains backward compatibility while providing the correct package
structure where all exports are available from the package root.

- Add /index.ts that re-exports all from /lib/index.ts
- Preserve existing /lib/index.ts structure

Author: bobymicroby

packages/entraid/index.ts

@@ -0,0 +1 @@
+export * from './lib/index'