conformance: prepare the conformance test suite

- move the conformance related files to a dedicated directory
- simplify parts of the conformance script
- create a scaffolding for a new GitHub action to run conformance tests
- use the new --output-dir flag from the conformance suite for saving
  results on demand

.github/workflows/conformance.yml

@@ -0,0 +1,38 @@
+name: Conformance Tests
+
+on:
+  # TODO: enable automatic triggering when tested.
+  # push:
+  #     branches: [main]
+  # pull_request:
+  workflow_dispatch:
+
+concurrency:
+  group: conformance-${{ github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+jobs:
+  server-conformance:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out code
+        uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4
+      - name: Set up Go
+        uses: actions/setup-go@d35c59abb061a4a6fb18e82ac0862c26744d6ab5 # v5
+        with:
+          go-version: "^1.25"
+      - name: Start everything-server
+        run: |
+          go run ./conformance/everything-server/main.go -http=":3001" &
+          # Wait for the server to be ready.
+          timeout 15 bash -c 'until curl -s http://localhost:3001/mcp; do sleep 0.5; done'
+      - name: "Run conformance tests" 
+        uses: modelcontextprotocol/conformance@c2f3fdaf781dcd5a862cb0d2f6454c1c210bf0f0 # v0.1.11
+        with:
+          mode: server
+          url: http://localhost:3001/mcp
+          suite: active
+          expected-failures: ./conformance/baseline.yml