Adds an in-memory per-(orbital, trait, entityId) field-state store consumed
by the compiled-path codegen so `(set @entity.X)` writes accumulate across
requests for [runtime] entities. Persistent entities continue to flow
through getDataService(). Without this, generated handlers' guards reading
@entity.X always saw {} on [runtime]-bound traits, blocking step-skip
protection (e.g. wizard step3 requiring step1/step2 commits).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>