[FEATURE] Surface the teleport command ("Open in CLI") directly in the Slack session message

Summary

When Claude Code runs a task from Slack (the @Claude / Claude Tag integration), it creates a Claude Code session on claude.ai/code and posts action buttons back to the thread. Today the only path to continue that session locally is: click View Session in Slack → open the web session in a browser → use the ⋮ menu's Open in ▸ Terminal action → copy the claude --teleport <session-id> command → paste into the terminal.

Please add a "Copy teleport command" (or "Open in terminal") action directly to the Slack completion message so a developer can grab claude --teleport <session-id> without the browser round-trip.

Before / After

Before (today):

1. Task finishes; Slack message shows View Session / Create PR.
2. Click View Session → browser opens the web session.
3. Use the web ⋮ menu → Open in ▸ Terminal → command is copied.
4. Paste claude --teleport <session-id> into the terminal.

After (proposed):

1. Task finishes; Slack message shows View Session / Create PR / Open in terminal.
2. Click Open in terminal → Slack surfaces claude --teleport <session-id> ready to copy.
3. Paste into the terminal.

Two clicks and a browser context switch removed for the common "I'll take it from here locally" flow.

The concrete ask

Add one more message action to the Slack completion message (alongside the existing View Session / Create PR / Retry as Code / Change Repo buttons) that exposes the same claude --teleport <session-id> string the web surface already produces. Any of these would satisfy it:

• A button that opens a small modal / code block containing the copyable command, or
• The command rendered inline in the thread as a formatted code snippet the user can copy.

The session ID is already known at the point the Slack message is posted, so no new data is required — it's the same string the web surface builds today.

Why this is low-risk / feasible

• The web already does exactly this. The web app's ⋮ menu has an Open in ▸ submenu with a Terminal option that surfaces the claude --teleport <session-id> command. This request is just mirroring that existing web affordance onto the Slack message.
• It's just surfacing a string. The value is claude --teleport <session-id>, generated from the existing session ID. This is presentation only — no new capability, no new auth surface.
• No local process launch. The action does not (and cannot) start anything on the developer's machine — Slack has no line to a local shell. It only puts text on the clipboard / in the thread; the developer runs it themselves. That's why a true "open my terminal and run it" button isn't possible, and precisely why this scoped "copy the command" version is safe and easy.
• Teleport auth is unchanged. Running the command still requires the developer to be signed in to the same claude.ai account with the CLI; the existing teleport requirements continue to gate actual access. Surfacing the command in Slack grants nothing new.

Related issues (not duplicates)

• #67309 — same handoff pattern, for a Chrome extension rather than Slack.
• #68486 — "Open in Claude Code CLI" option in the Desktop app (closed).

Docs

• Claude Code in Slack: https://code.claude.com/docs/en/slack
• Claude Code on the web (the web "Open in CLI" / teleport action): https://code.claude.com/docs/en/claude-code-on-the-web