Phase V landed: app_version module, ext-state version stamp, show-version
action, beta-in-isolation channel build. CLAUDE.md gains the module entry,
version key, test target, and beta-build note.
Add docs/product/versioning-and-release.md and a PLAN.md Phase V pointer
laying out release versioning and the beta side-channel as decidable
options (V1-V4, unsettled - awaiting Daniel).