Team dashboard as a canvas in the GitHub Copilot app #2461

Part of #2438 (a follow-up, after the Claude dashboard ships). Needs research.

Goal

Show the same team view (Board, Roadmap and Conversation) in the GitHub Copilot app, as a canvas that opens on its own when Squad runs there, the way /squad:dashboard opens it for Claude Code users.

Why

The Claude Code end-to-end test showed that a live team view makes Squad's multi-agent behaviour much easier to follow. Copilot users should get the same thing, and both hosts should share one view so the experience is the same.

What needs to be done

• Research first: confirm what the Copilot SDK's canvas support allows today (it's experimental: createCanvas via joinSession({ canvases })): what a canvas can render, how it updates, and whether an extension can open one automatically. Record the findings in this issue.
• A Copilot event source: map Copilot session events (user.message, subagent and tool events, session.idle, session.error) to the same normalized events the Claude reader produces (Claude team dashboard: read live Claude Code sessions instead of captured stream-json #2459), so the page and the lane logic are shared and not forked.
• Render the shared page (or a canvas-friendly version of it) in the canvas, following the app's light/dark theme.
• Decide when it opens: automatically when a Squad session starts, or on a command. Opening automatically should be something the user can turn off.
• Tests for the Copilot event mapping against a fixture session.

Done when

• A Squad session in the Copilot app can show the team view in a canvas, using the same page and event model as the Claude Code dashboard.
• If the canvas API can't support it yet, this issue records why, and what would unblock it.