One lever, every surface. The renderer toggle persists locally and mirrors
into display.message_reactions; the backend gates the agent's
react_to_message tool (check_fn) and the model-context annotation on the same
key, and the ':' composer trigger reads the store at detection time. Off
means off everywhere: no ☺ slot, no right-click picker, no :shortcode:
popover, no agent reactions, and the model hears nothing — while reactions
already persisted keep rendering so history doesn't lose data. Also fixes the
import-order lint error CI flagged in composer/index.tsx.
Reactions live in the existing messages.display_metadata JSON column (no new
table), with iOS Tapback semantics enforced DB-side: one reaction per author
per message, re-tap retracts, different emoji replaces. The desktop catches up
to the reaction contract five platform adapters already ship.
- SessionDB: set/get_message_reaction, latest_message_row_id (role + offset +
require_text so invisible tool-call-only rows are never targeted),
take_unseen_reactions (announce-exactly-once), get_message_role
- message.react RPC: accepts row_id or newest_role for live messages that
haven't learned their durable id yet
- react_to_message tool: desktop-gated (check_fn), defaults to the user's
latest visible message, messages_back for retroactive reactions
- Model context rides run_message only (beside the speech-interrupted note):
the persisted prompt stays clean, so no [The user reacted …] scaffolding in
transcripts, and no cached prefix ever changes
- Resume projection forwards row_id + reactions; _row_id is stripped from
outgoing API copies next to display_metadata
