Group Attribute(...) delegating through the public memoized AttributeKey(name)
cache meant a direct [AttributeKey "name"]=v write and a group field (or two
independent groups) targeting the same name silently converged on the same
dispatch slot -- last write wins, no error. Fix: groups use rawNew(name) to
mint a private per-name key cached on their own (inst,index) relation instead
of the shared cache, so AttributeKeyHandler can detect a conflicting claimant
by simple object-identity comparison -- no separate ownership registry needed.
Persisting names reuse the same cached key across group value swaps, so the
existing diff (nil only what left, leave the rest alone) keeps working.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
