// BackendBox — backend tag holder (no execution in Phase 15.7)
box BackendBox {
  name
  birth(n) { if n == null { n = "vm" } me.name = n return 0 }
  get_name() { return me.name }
  // Stub execute: reserved for future; returns 0 for now
  execute(_mir_json) { return 0 }
}

static box BackendStub { main(args) { return 0 } }

