[Bug] Slack MCP connector footer causes self-mention loop with Claude app

Bug Description
Recommended to submit here. Please review transcript and issue description: Thanks — the last message confirmed what I suspected: the attribution settings in settings.json only control git commit/PR attribution, not the Slack connector footer. So the Fin AI's fix was a dead end. Please disregard that thread of advice. Let me describe the actual bug so you can route it correctly: What the connector does: Every message sent via the Slack MCP connector (mcp__23fb4be0-717b-4e3f-859b-b99afd3a6450__slack_send_message) has Sent using <@U0A2KQ798JX|Claude> auto-appended by the connector itself — after my generated content, before Slack receives it. I confirmed this with a control test: I sent a message with an explicit "body ends here" sentinel and no attribution in the body. The footer was appended anyway. The text never passes through anything I control, so no prompt, skill, system instruction, or settings.json key can suppress it. Why it causes a loop: U0A2KQ798JX is the user ID of the Claude Slack app itself. Because the footer uses the <@U...|Claude> mention syntax, Slack renders it as a live mention and fires a mention event back to the same app. The Claude app then responds with its default "pick a repository" / "your Claude Code session is complete" prompts into the channel. Every scheduled Cowork task that posts to Slack kicks off this bounce-back. What I've already ruled out: Not fixable via prompt edits or skill instructions (text is injected after Claude). Not fixable in my settings.json (attribution.commit/attribution.pr are git-only). Not fixable at api.slack.com/apps (I don't own the Claude app, so it doesn't appear in my app list). /status shows no managed settings overrides on my side. The fix I'm requesting: Change the connector's footer from the live mention <@U0A2KQ798JX|Claude> to plain text (e.g., Sent using Claude). That preserves attribution without self-triggering the Claude Slack app. This would need to ship on the Anthropic/connector side — there's no user-side lever. Can you file this as a bug against the Slack MCP connector and share a ticket number? Conversation ID for reference: 215474025586338.

Environment Info

• Platform: win32
• Terminal: vscode
• Version: 2.1.117
• Feedback ID: 0b4fc042-98f1-438e-8ee3-f457717d6508

Errors

[{"error":"Error: 127: Command 'code.cmd' not found or is in an unsafe location (current directory) Command 'code.cmd' not found or is in an unsafe location (current directory)\n    at oLf (B:/~BUN/root/src/entrypoints/cli.js:1762:4045)\n    at async iLf (B:/~BUN/root/src/entrypoints/cli.js:1762:1435)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-22T21:00:48.339Z"}]