feat: add python-sdk as a built-in SDK runner target (#329)

* feat: add python-sdk as a built-in SDK runner target

Wire modelcontextprotocol/python-sdk into the `conformance sdk` runner
alongside typescript-sdk and go-sdk, using the SDK's existing conformance
fixtures for both client and server modes.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* feat: target python-sdk v1.x on spec 2025-11-25

Convert the built-in python-sdk entry from v2/main to python-sdk-v1,
mirroring typescript-sdk-v1: clone the v1.x branch, default specVersion
to 2025-11-25 so draft-only scenarios/checks are excluded, and point at
the SDK's own expected-failures baseline. v2/main is mid-refactor and
noisy; v1.x is the stable published line.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* feat: default sdk-runner server mode to the `active` suite

Server runs previously fell through to the underlying `server` command's
default; make it explicit and consistent with tiering, which runs the
`active` suite (excludes pending/draft). Avoids surfacing intentionally
-deferred `pending` scenarios (e.g. json-schema-2020-12, server-sse
-polling) as failures. Runner-wide default for all SDKs; callers can
still override with --suite.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/sdk-runner/known-sdks.ts

@@ -45,6 +45,29 @@ export const KNOWN_SDKS: Record<string, SdkConfig> = {
       command: './.conformance-server -http=:3000',
       url: 'http://localhost:3000'
     }
+  },
+  // v1.x — the stable, published line of the python-sdk, analogous to
+  // typescript-sdk-v1 (v2/main is mid-refactor and noisy). Clones the
+  // python-sdk repo, defaulting to the `v1.x` branch, and targets the latest
+  // dated spec so draft-only scenarios/checks are excluded by default. uv
+  // workspace: the `mcp` (client) and `mcp-everything-server` (server) packages
+  // are both members, so one `uv sync --all-packages` covers both modes.
+  // Fixtures live in the python-sdk repo (.github/actions/conformance/ and
+  // examples/servers/everything-server). `--port 3000` matches the url and the
+  // 3000 convention used above; the server's own default is 3001.
+  'python-sdk-v1': {
+    repo: 'python-sdk',
+    defaultRef: 'v1.x',
+    specVersion: '2025-11-25',
+    build: 'uv sync --frozen --all-extras --all-packages',
+    client: {
+      command: 'uv run --frozen python .github/actions/conformance/client.py'
+    },
+    server: {
+      command: 'uv run --frozen mcp-everything-server --port 3000',
+      url: 'http://localhost:3000/mcp'
+    },
+    expectedFailures: '.github/actions/conformance/expected-failures.yml'
   }
 };