Run interviews in Slack channels with live streaming

• Native Slack interview thinking and streaming, so participants see responses appear in real time.
• Channel @mention support: interviews now work in channels with the same active-conversation handling as direct messages, plus a branded call-to-action when no conversation is active.
• Slack file-share replies with text are now accepted (the attachments themselves are ignored).

• Slack mentions and links are preserved through automation and interview replies, including the final streamed message.
• Restarting a Slack interview now reuses the same interview but starts a fresh direct-message thread, cleaning up the old one.

Routine security and dependency updates to keep your data safe.