feat: Add TypeScript declaration file for mongoose module

This declaration file ensures proper TypeScript support for the mongoose module by re-exporting its types. It improves type safety and developer experience when using mongoose in TypeScript projects.

src/interfaces/mongoose.d.ts

@@ -0,0 +1,4 @@
+declare module "mongoose" {
+  import * as mongoose from "mongoose";
+  export = mongoose;
+}