feat(ui-flow): mark-channel-read emits threadChannelId for desktop dismiss

Thread mark-read cleared events include threadChannelId so the desktop UI
can dismiss thread-family notifications alongside parent channel batch.

Co-authored-by: Cursor <[email protected]>

README.md

@@ -48,7 +48,7 @@ Returns `false` for unknown types (caller may log).
 | Boosts / stickers | `contribute-guild-boost`, `upsert-guild-sticker`, `upsert-sticker-pack` |
 | Profile | `update-profile-cosmetics`, `set-profile-banner-image`, step-up PIN types |
 | Voice / screen | `join-voice`, `join-voice-listen`, `join-stage`, `voice-capture-chunk`, `display-capture-frame` |
-| Notifications | `mark-all-notifications-read` (emits `mark-all-notifications-read-cleared`, v0.8.283), `mark-notification-read` (emits `mark-notification-read-cleared` + `notificationChannelId`, v0.8.286), `mark-channel-read` (emits `mark-channel-read-cleared`, v0.8.284), `refresh-notifications` (v0.8.236) |
+| Notifications | `mark-all-notifications-read` (emits `mark-all-notifications-read-cleared`, v0.8.283), `mark-notification-read` (emits `mark-notification-read-cleared` + `notificationChannelId`, v0.8.286), `mark-channel-read` (emits `mark-channel-read-cleared` + `threadChannelId` for threads, v0.8.287), `refresh-notifications` (v0.8.236) |
 | Workers | `export-integration-worker-script`, `run-worker-install-trial`, `announce-worker-release` |
 | Moderation / channels | `ban-member`, `upsert-channel-overwrite`, forum/thread types |
 | Search | `update-search`, `refresh-search`, `remove-search-recent` (v0.8.140) |

index.js

@@ -552,7 +552,8 @@ async function dispatchUiMessage (platform, msg, hooks = {}) {
       send({
         type: 'mark-channel-read-cleared',
         guildId,
-        channelId: dismissChannelId
+        channelId: dismissChannelId,
+        threadChannelId: ch?.type === 'thread' ? msg.channelId : undefined
       })
     }
     return true