docs: add Server Card roadmap priorities (#47)

The WG's proposed priorities for the core-maintainer roadmap, per the
Jul 27 meeting. Three tracks, in priority order:

1. **Graduate the Server Card as an official MCP extension** — gated on
merging an SDK reference impl (Python [python-sdk#2951], Go
[go-sdk#1024], TS [typescript-sdk#2527]), landing best practices
([#40]/[#36]), and keeping the GitHub showcase ([#34]) in sync.
2. **Describe what a server does, not just where to reach it** — the
primitives / static-capability work ([#30]), framed around the problem:
a card lists URLs but no operations for consumers that never connect.
3. **Authentication** — express real-world per-remote auth ([#13]); land
a limited shape first, expand as a fast-follow.

Kept deliberately short as a strawman for public comment. Docs-only;
`format:check` passes.

[python-sdk#2951]:
https://github.com/modelcontextprotocol/python-sdk/pull/2951
[go-sdk#1024]: https://github.com/modelcontextprotocol/go-sdk/pull/1024
[typescript-sdk#2527]:
https://github.com/modelcontextprotocol/typescript-sdk/pull/2527
[#13]:
https://github.com/modelcontextprotocol/experimental-ext-server-card/issues/13
[#30]:
https://github.com/modelcontextprotocol/experimental-ext-server-card/issues/30
[#34]:
https://github.com/modelcontextprotocol/experimental-ext-server-card/issues/34
[#40]:
https://github.com/modelcontextprotocol/experimental-ext-server-card/issues/40
[#36]:
https://github.com/modelcontextprotocol/experimental-ext-server-card/pull/36

---------

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 904e057e-7dd0-4dfc-9e15-571ddeb8475f
Copilot-Session: 2eabcc66-5630-47ce-b193-171bbcaff1e8

docs/core-maintainer-roadmap.md

@@ -0,0 +1,44 @@
+# Server Cards: Roadmap Priorities
+
+The Server Card working group's proposed priorities for the core-maintainer
+roadmap. Maintainers are consolidating the roadmap around an upcoming spec
+release. These are the three themes, in priority order, we want carried into that
+roadmap.
+
+## 1. Unlock MCP Discovery
+
+The next step is to graduate the Server Card to an official MCP extension as
+Server Cards are still experimental. [SEP-2127] is in review, and the
+Extensions Track ([SEP-2133]) also requires a merged SDK reference implementation.
+Getting to an accepted, adoptable extension is the top priority. This will
+unlock MCP as a part of a discoverable web of agents.
+
+## 2. Describe what a server does
+
+A card today says _where_ to connect but not _what_ the server can do. That
+blocks consumers from using Server Cards for richer discovery and informing
+end users of what to expect. `server/discover` and list endpoints are
+frequently gated by auth, so an enriched server card would help significantly.
+Primitives were deliberately removed from the card ([PR #19]); this track
+revisits adding them back for static discovery.
+
+## 3. Authentication
+
+Cards need to express real-world auth well enough that a client can actually
+connect. Auth is per-remote and varies across endpoints, and reviewers have
+raised scenarios the current shape doesn't cover ([#13], core-spec
+[PR #2742][pr2742]).
+
+[sep-2127]: https://github.com/modelcontextprotocol/modelcontextprotocol/pull/2127
+[SEP-2133]: https://github.com/modelcontextprotocol/modelcontextprotocol/pull/2133
+[pr2742]: https://github.com/modelcontextprotocol/modelcontextprotocol/pull/2742
+[python-sdk#2951]: https://github.com/modelcontextprotocol/python-sdk/pull/2951
+[go-sdk#1024]: https://github.com/modelcontextprotocol/go-sdk/pull/1024
+[typescript-sdk#2527]: https://github.com/modelcontextprotocol/typescript-sdk/pull/2527
+[#13]: https://github.com/modelcontextprotocol/experimental-ext-server-card/issues/13
+[#16]: https://github.com/modelcontextprotocol/experimental-ext-server-card/issues/16
+[#30]: https://github.com/modelcontextprotocol/experimental-ext-server-card/issues/30
+[#34]: https://github.com/modelcontextprotocol/experimental-ext-server-card/issues/34
+[#40]: https://github.com/modelcontextprotocol/experimental-ext-server-card/issues/40
+[PR #19]: https://github.com/modelcontextprotocol/experimental-ext-server-card/pull/19
+[PR #36]: https://github.com/modelcontextprotocol/experimental-ext-server-card/pull/36