Merge release/v5-prerelease (socket.yml landed)

Brings in #293, the socket.yml rollout config this branch builds on.
This branch already carries every change #293 made, so every conflict
resolves to this branch's side and the tree matches the previous head
exactly. No code changed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AvGSu5jGg1z3f3sePc2eHC

Author: claude