feat: stub master file structures

crates/nxmesh-master/src/grpc/interceptor.rs

@@ -0,0 +1,9 @@
+//! gRPC interceptors
+
+use tonic::{Request, Status};
+
+/// Authentication interceptor
+pub fn auth_interceptor(req: Request<()>) -> Result<Request<()>, Status> {
+    // TODO: Implement authentication
+    Ok(req)
+}