fix(slack): pass recipient_team_id and recipient_user_id to streaming API calls

The Slack Agents & AI Apps streaming API (chat.startStream / chat.stopStream)
requires recipient_team_id and recipient_user_id parameters. Without them,
stopStream fails with 'missing_recipient_team_id' (all contexts) or
'missing_recipient_user_id' (DM contexts), causing streamed messages to
disappear after generation completes.

This passes:
- team_id (from auth.test at provider startup, stored in monitor context)
- user_id (from the incoming message sender, for DM recipient identification)

through to the ChatStreamer via recipient_team_id and recipient_user_id options.

Fixes #19839, #20847, #20299, #19791, #20337

AI-assisted: Written with Claude (Opus 4.6) via OpenClaw. Lightly tested
(unit tests pass, live workspace verification in progress).

src/slack/monitor/message-handler/dispatch.ts

@@ -199,6 +199,8 @@ export async function dispatchPreparedSlackMessage(prepared: PreparedSlackMessag
           channel: message.channel,
           threadTs: streamThreadTs,
           text,
+          teamId: ctx.teamId,
+          userId: message.user,
         });
         replyPlan.markSent();
         return;

src/slack/streaming.ts

@@ -36,6 +36,18 @@ export type StartSlackStreamParams = {
   threadTs: string;
   /** Optional initial markdown text to include in the stream start. */
   text?: string;
+  /**
+   * The team ID of the workspace this stream belongs to.
+   * Required by the Slack API for `chat.startStream` / `chat.stopStream`.
+   * Obtain from `auth.test` response (`team_id`).
+   */
+  teamId?: string;
+  /**
+   * The user ID of the message recipient (required for DM streaming).
+   * Without this, `chat.stopStream` fails with `missing_recipient_user_id`
+   * in direct message conversations.
+   */
+  userId?: string;
 };
 
 export type AppendSlackStreamParams = {
@@ -64,13 +76,17 @@ export type StopSlackStreamParams = {
 export async function startSlackStream(
   params: StartSlackStreamParams,
 ): Promise<SlackStreamSession> {
-  const { client, channel, threadTs, text } = params;
+  const { client, channel, threadTs, text, teamId, userId } = params;
 
-  logVerbose(`slack-stream: starting stream in ${channel} thread=${threadTs}`);
+  logVerbose(
+    `slack-stream: starting stream in ${channel} thread=${threadTs}${teamId ? ` team=${teamId}` : ""}${userId ? ` user=${userId}` : ""}`,
+  );
 
   const streamer = client.chatStream({
     channel,
     thread_ts: threadTs,
+    ...(teamId ? { recipient_team_id: teamId } : {}),
+    ...(userId ? { recipient_user_id: userId } : {}),
   });
 
   const session: SlackStreamSession = {