Symposium references

A symposium reference is a way for your IDE or other tools to communicate with your agent. It works by pasting a small bit of XML, something like <symposium-ref id="..."/> into your chat; the UUID that appears in that reference is also sent to the MCP server, along with some other information. The agent can then use the expand_reference tool to read that extra information. This mechanism is used when you select text and choose "Discuss in Symposium" or when you reply to comments in a walkthrough. You can embed multiple references, whatever makes sense to you.