alivesystem-upgrade

# System Upgrade Upgrade an ALIVE world from any prior version to the current target. The skill is a thin operator-facing surface; the work happens in the `system_upgrade/` Python package shipped with the plugin (orchestrator + 13 locked phases). Stdlib-only, no PyYAML/ruamel. If you are reading this on the old monolithic skill (476 lines of inline upgrade logic), that file has been retired in favour of the orchestrator. This file documents what the operator and skill agent need to know to drive it. --- ## When It Fires - The human runs `/alive:system-upgrade` (any version of the world — v1, v2, v3.0, v3.1, v3.2). - The session-new hook detects a legacy structure and surfaces the upgrade prompt. - The human says "upgrade my world", "migrate to the new version", "update alive". - The human asks to inspect or restore an earlier upgrade tarball (`--rollback`). --- ## Tool version vs world version Two distinct version concepts; the orchestrator never confuses them. - **Tool version** — read from `plugins/alive/.claude-plugin/plugin.json` `version`. The version of the migrator currently installed. Used for `--resume` plugin-version-skew validation and the upgrade record's `tool_version_at_run` field. Never feeds world-version inference; never feeds the no-op short-circuit. - **World version** — derived from world content fingerprints only: path/file existence, bundle schema fingerprints, hook/script content patterns. Three signals, not four. Lowest-version-wins. When zero...