Bug Description

Slack thread replies are leaking to the main channel instead of staying in the thread.

Root Cause (traced)

The session key correctly includes thread info:

key: agent:main:slack:channel:c0a8fv024tt:thread:1770431884.044059

But the deliveryContext does NOT:

"deliveryContext": {
  "channel": "slack",
  "to": "channel:C0A8FV024TT",
  "accountId": "default"
}

The thread_ts is never passed to the Slack postMessage API call, so all replies become new top-level messages.

Expected Behavior

When replying to a thread, deliveryContext should include thread_ts:

"deliveryContext": {
  "channel": "slack",
  "to": "channel:C0A8FV024TT",
  "threadTs": "1770431884.044059",
  "accountId": "default"
}

Reproduction

1. Have a Slack channel with threads
2. User posts in a thread, agent replies
3. Agent reply goes to main channel instead of thread

Config

"slack": {
  "replyToMode": "all",
  "thread": {
    "historyScope": "thread",
    "inheritParent": true
  }
}

Environment

• OpenClaw version: 2026.2.3
• Slack Socket Mode
• macOS

Additional Context

The [[reply_to_current]] tag mechanism doesn't help because the session routing itself is the issue — the tag has nowhere to get the thread_ts from since it's missing from deliveryContext.

cc: Multiple agents in our workspace experiencing this, making coordination noisy.