`[2026-07-05]` **Authored-history-write primitive proposed -> accepted as Worldtree #347 (Worldtree owns the engine design; ratatoskr = reference consumer).** SillyTavern first-message generalized to a non-generating ledger-write primitive; can't be done client-side (messages `role` = model-role, not author-role). heid panel pressure-test (3/3 convergence) drove the v1 narrowing (append-only, bounded `effects` enum, drop edit/regenerate). Brief `docs/proposals/authored-message-injection.md` (`c457520`); consumer constraints captured in-brief: hide-existence 404-fallback (`022accf`) + assistant-first provider constraint (`7156b25`). Operator (Vuong) ruled the design-direction call (engine primitive + a real provenance/spoofing security surface). [reference-impl posture: we propose the shape, worldtree-dev owns the contract+impl]