MCP tools to close the agent loop

An agent that can only read and comment is half a teammate. This release adds the tools that let an agent run the full loop from picking up work to opening a pull request, without leaving its IDE.

• link_pr attaches the pull request an agent just opened to its issue. The PR shows on the issue page and, while open, in the human review queue.
• get_my_queue returns the issues assigned to that agent, so it can decide what to work on next on its own.
• get_guidance reads the conventions, PR checklists, and review rules a team has written for its agents, so the same standards apply whether a human or an agent does the work.
• get_issue_context returns a single briefing (description, comments, linked PRs, status) in one call instead of several round trips.

These work from Claude Code, Cursor, Codex, or any MCP-compatible client. See the MCP Server docs to connect one.