upgrading-megapowerslisted

# Upgrading Megapowers Use the current marketplace [channel reference](references/channels.md). Before any write, inventory visible registrations: enabled state and version, exposed scope, marketplace name and source, pin or ref, local edits, duplicates, caches, and active sessions. Read the stable release and changelog without writes. Stop on ambiguous provenance, managed-source edits, or conflicting installations. Preserve enabled state, source or channel, scope, pin, and local edits. A floating Git marketplace follows its latest stable release; a pinned or local checkout changes only when explicitly approved. Keep one installation channel per harness and exclude unrelated cleanup. If already current, report a verified no-op. Resolve the stable release tag to its exact commit and the observed marketplace source's tracked head: its `release` branch when the registration carries that ref, otherwise its default branch. A floating refresh may proceed only when the release commit and marketplace head match. Otherwise stop before any write; never install unreleased branch state as a stable upgrade. A registration that tracks the default branch is a channel defect: report it and propose re-registering at `release` as a separately approved write. After refreshing but before registration, resolve the snapshot commit and require it to match the approved commit. Otherwise stop with the installed plugin untouched. Request one exact approval covering target harnesses, enabled state