Build the full reaction pipeline on top of the #29916 base:
- Opt-in gate: slack.reaction_triggers (default OFF — reaction events
stay acked-and-dropped so busy channels don't wake the agent on every
emoji). 'true' routes reactions on the bot's OWN messages; an explicit
emoji-name list routes those emojis from any message (handoff flows).
- reaction_removed events now route too, distinguished by the
cross-platform text convention reaction:added:<emoji> /
reaction:removed:<emoji> (matches the Feishu and Photon adapters, so
agents and skills see one shape everywhere).
- Authorization: the reactor becomes the synthesized message's user, so
the early _is_user_authorized gate and allowed_channels whitelist
apply exactly as for typed messages. _hermes_force_process only skips
the mention requirement (a reaction on the bot's own message is
definitionally addressed to the bot), mirroring Feishu/Photon.
- Gateway hooks (#33111 by @johnkattenhorn): every human reaction on a
message item fires reaction:added / reaction:removed through the new
BasePlatformAdapter.set_reaction_handler → GatewayRunner
._handle_reaction_event → HookRegistry.emit, independent of the
routing opt-in. Documented in hooks.md.
- Channel handoff (#45265 by @Kev-fs): slack.reaction_trigger_target
routes the reaction turn to a configured channel (top-level via
_hermes_no_thread_response + reply-anchor suppression in
gateway/platforms/base.py) or C123:<ts> thread.
- Manifest: reaction_removed event subscription added alongside
reaction_added/reactions:read.
- Docs: slack.md Reaction Triggers section; hooks.md event table rows.
Also credits #44508 by @harrisonmedmedmetrics (inbound reaction_added
handling — same plumbing class, superseded by this consolidated shape).
Co-authored-by: johnkattenhorn <john.kattenhorn.personal@gmail.com>
Co-authored-by: Kev-fs <kevin@fleetsmarts.net>
Co-authored-by: harrisonmedmedmetrics <harrison@medmetricsrx.com>
