v2.3.0

/.well-known/mcp/server-card.json discovery endpoint

A pragmatic approximation of SEP-2127
("MCP Server Cards -- HTTP Server Discovery", superseding the withdrawn
SEP-1649) -- which is not a ratified part of the MCP spec: the PR is
still open, and even its own well-known path has shifted between drafts
(some revisions use .well-known/ai-catalog.json instead of this one).

If SEP-2127 (or a successor) ratifies with a different
path/shape, this endpoint will need to change to match.

Generated live from the actual tool registry (mcp.list_tools()) on every
request rather than a static file, so it reports the real 39 tools with
accurate schemas and can't drift out of sync as tools are added or changed.