refactor: centralize ack reaction gating

src/plugin-sdk/index.ts

@@ -117,6 +117,8 @@ export {
   resolveMentionGating,
   resolveMentionGatingWithBypass,
 } from "../channels/mention-gating.js";
+export type { AckReactionGateParams, AckReactionScope } from "../channels/ack-reactions.js";
+export { shouldAckReaction } from "../channels/ack-reactions.js";
 export { resolveChannelMediaMaxBytes } from "../channels/plugins/media-limits.js";
 export type { NormalizedLocation } from "../channels/location.js";
 export { formatLocationText, toLocationContext } from "../channels/location.js";