3.x — vision (history slot)

Per-era vision record for the 3.x architecture track. This is part of the versioned history beneath the living architecture (see ../../README.md for the boundary and decay rules).

The 3.x era is the current track: forward vision lives in the living top-level docs/architecture/vision/, and current-era ADRs land in docs/adr/3.x/. This slot receives 3.x vision statements once they are demoted — i.e. when a piece of the living vision is no longer current or future. History accrues by version; nothing is deleted.

Empty until a living vision artifact decays into the 3.x era.