User cited https://luau.org/compatibility/ (Lua 5.2 section, "Ephemeron
tables") -- Luau explicitly did not adopt this due to complexity. Upgrades
the previous session's defensive "unverified, avoid just in case" framing
to a confirmed fact: two separate Relates strongly cross-referencing each
other's keys is a real, unrecoverable leak in Luau, not just a theoretical
risk. Adds a general rule to relate-plan.md so future Relate designs don't
have to rediscover this from scratch.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
