chore: import upstream snapshot with attribution

.github/workflows/conformance.yml

@@ -0,0 +1,79 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+name: conformance
+# zizmor flags pull_request_target, but it is safely gated by the 'tests: run' label manually applied by maintainers.
+on: # zizmor: ignore[dangerous-triggers]
+  pull_request:
+  pull_request_target:
+    types: [labeled]
+
+permissions: read-all
+
+jobs:
+  conformance:
+    if: "${{ github.event.action != 'labeled' || github.event.label.name == 'tests: run' }}"
+    name: conformance
+    runs-on: ubuntu-latest
+    concurrency:
+      group: ${{ github.workflow }}-${{ github.ref }}
+      cancel-in-progress: true
+    permissions:
+      contents: 'read'
+      issues: 'write'
+      pull-requests: 'write'
+    steps:
+      - name: Remove PR Label
+        if: "${{ github.event.action == 'labeled' && github.event.label.name == 'tests: run' }}"
+        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            try {
+              await github.rest.issues.removeLabel({
+                name: 'tests: run',
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: context.payload.pull_request.number
+              });
+            } catch (e) {
+              console.log('Failed to remove label. Another job may have already removed it!');
+            }
+            
+      - name: Checkout code
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
+          repository: ${{ github.event.pull_request.head.repo.full_name }}
+          token: ${{ secrets.GITHUB_TOKEN }}
+          persist-credentials: false
+          
+      - name: Setup Go
+        uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6.4.0
+        with:
+          go-version-file: 'go.mod'
+          
+      - name: Start MCP Toolbox Server
+        run: |
+          go build -o toolbox
+          ./toolbox --allowed-hosts localhost --config tests/conformance/tools.yaml &
+          sleep 5 # Give the server a moment to bind to port 5000
+
+      - name: Run Conformance Tests
+        uses: modelcontextprotocol/conformance@21a9a2febd7100d7c17ac1021ee7f2ed9f66a1e0 # v0.1.16
+        with:
+          mode: server
+          url: 'http://localhost:5000/mcp'
+          suite: active
+          expected-failures: tests/conformance/conformance-baseline.yml