Allow full Slack thread capture when posting to Timeline via Sally

Title
Allow full Slack thread capture when posting to Timeline via Sally

Description
Sally currently only posts one Slack message at a time to Timeline, using the message shortcut or the "Post to timeline of [customer name]" command. CSMs often use internal Slack channels to discuss a specific account, and the full context lives across a thread, not just one message.

It would help to have a way to capture an entire thread, including the parent message and all replies, in a single Timeline post. Right now the only workaround is to manually copy and paste the rest of the thread into the Notes field, which is time consuming and easy to miss details on.

This would save CSMs time and make sure the full account context is preserved in Timeline without manual copy and paste work.