Bug Description

Subagent completion announcements via sessions_spawn land in the General topic (Topic 1) of Telegram forum groups instead of the originating thread/topic.

Root Cause

In src/agents/subagent-announce.ts, the sendSubagentAnnounceDirectly() function has two delivery paths:

1. Direct send path (used when expectsCompletionMessage: true, which is always the case for sessions_spawn):

   await callGateway({
     method: "send",
     params: {
       channel: completionChannel,
       to: completionTo,
       accountId: completionDirectOrigin?.accountId,
       // ❌ threadId is MISSING here
       sessionKey: canonicalRequesterSessionKey,
       message: params.completionMessage,
       idempotencyKey: params.directIdempotencyKey,
     },
   });

2. Fallback agent path (correctly includes threadId):

   await callGateway({
     method: "agent",
     params: {
       // ...
       threadId: params.requesterIsSubagent ? undefined : threadId, // ✅ included
       // ...
     },
   });

The to field in session delivery context stores just the group ID (e.g., telegram:-100XXXXXXXXXX) without topic encoding, while threadId is stored as a separate field. Since the direct send path doesn't include threadId, Telegram delivers to the General topic.

Impact

• All sessions_spawn completions in Telegram forum topic threads land in the wrong topic
• The completionDirectOrigin object has threadId available but it's simply not being extracted/passed

Steps to Reproduce

1. Set up a Telegram group with forum topics enabled
2. Send a message in a non-General topic that triggers sessions_spawn
3. Wait for the subagent to complete
4. Observe: announcement appears in General topic instead of the originating topic

Fix

Extract threadId from completionDirectOrigin and pass it to the send call:

const completionThreadId =
  completionDirectOrigin?.threadId != null && completionDirectOrigin.threadId !== ""
    ? String(completionDirectOrigin.threadId)
    : undefined;
await callGateway({
  method: "send",
  params: {
    channel: completionChannel,
    to: completionTo,
    accountId: completionDirectOrigin?.accountId,
    threadId: completionThreadId,  // ← add this
    sessionKey: canonicalRequesterSessionKey,
    message: params.completionMessage,
    idempotencyKey: params.directIdempotencyKey,
  },
  timeoutMs: 15_000,
});

Environment

• OpenClaw version: 2026.2.18
• Platform: macOS (arm64)
• Channel: Telegram (forum-enabled group)