Slack bridge sends raw markdown instead of Slack mrkdwn format

[ofhtech]

Bug Report

Version: Agent Deck v0.25.1
OS: Linux 6.6.87.2 (WSL2)
tmux: 3.4

Description

The conductor Slack bridge forwards conductor responses as raw GitHub-flavored markdown, which Slack doesn't render. Slack uses its own mrkdwn format — e.g., *bold* instead of **bold**, no # headers, • bullets instead of - .

Steps to Reproduce

1. Set up a conductor with Slack bridge (agent-deck conductor setup)
2. Send a message that triggers a response with markdown formatting (bold, headers, bullet lists)
3. Response appears in Slack with raw **text**, ## headers, and - bullets

Expected vs Actual

Expected: Formatted text in Slack (bold, bullets, links rendered)
Actual: Raw markdown syntax displayed as plain text

Solution

Added a _markdown_to_slack() converter in bridge.py that transforms responses before posting via say():

def _markdown_to_slack(text: str) -> str:
    """Convert GitHub-flavored markdown to Slack mrkdwn format."""
    text = re.sub(r"^#{1,6}\s+(.+)$", r"*\1*", text, flags=re.MULTILINE)  # headers
    text = re.sub(r"\*\*(.+?)\*\*", r"*\1*", text)  # bold
    text = re.sub(r"~~(.+?)~~", r"~\1~", text)  # strikethrough
    text = re.sub(r"\[([^\]]+)\]\(([^)]+)\)", r"<\2|\1>", text)  # links
    text = re.sub(r"^(\s*)[-*]\s+", r"\1• ", text, flags=re.MULTILINE)  # bullets
    return text

Applied in _safe_say() so all Slack responses are converted automatically.