Update node main instance management

Editor assessment

The subject's phrasing, update node main instance management, is administrative rather than descriptive: it names the subsystem but reveals nothing about what was reorganized, what problem prompted it, or how behavior differs afterward. The refactor type fits an internal restructuring, no scope is attached, and no body or footers exist to supply the missing substance. No hygiene violations appear beyond the vagueness itself. A maintainer deep in that subsystem may reconstruct the intent, but the message as written communicates a motion without a direction, which is the weak-teaching profile.