Bug Description

Top-level Slack channel messages are being assigned a :thread: session key suffix when thread_ts == ts (i.e., the message is its own thread parent, not a reply). This causes every new top-level message in the channel to create a fresh isolated session, resulting in complete context loss between messages.

Environment

• Version: v2026.3.1
• Channel: Slack
• Config: replyToMode: "off", thread.historyScope: "channel", thread.inheritParent: true

Steps to Reproduce

1. Send a top-level message to a Slack channel (not a thread reply)
2. Observe the session key generated for that message

Expected Behavior

Session key should be: agent:main:slack:channel:c0ac4m19zdl

Actual Behavior

Session key is: agent:main:slack:channel:c0ac4m19zdl:thread:1772498423.706199

The thread_ts (1772498423.706199) equals the message's own ts (1772498423.706199), which per Slack's API spec means the message is a top-level channel message — not a thread reply. OpenClaw is incorrectly treating these as threaded messages.

Impact

• Every top-level channel message creates an isolated session
• Complete context loss between messages in the same channel
• Bot cannot maintain conversation continuity in Slack channels

Suggested Fix

When determining session key for Slack messages, check if thread_ts == ts. If true, the message is a top-level post and should use the channel-scoped session key (without the :thread: suffix), not a thread-scoped key.

if (message.thread_ts && message.thread_ts !== message.ts) {
  // actual thread reply → use thread-scoped session
} else {
  // top-level message → use channel-scoped session
}

Workaround

Set historyLimit: 200 as a bandaid to provide more context within each isolated session, but this does not address the root cause.