Streamline README and add conformance score badges (#312)

- Add a shields.io badge row to the README header (version, CI, PHP
  version, license, conformance scores, protocol/spec) to match the
  other official MCP SDKs.
- Expand "PHP Libraries Using the MCP SDK" into a curated, alphabetically
  sorted list of downstream projects.
- Add tests/Conformance/bin/score.php, a Symfony Console command that
  turns a conformance run's --output-dir into a shields.io endpoint JSON.
- Extend the weekly conformance workflow to score each run and publish
  the client/server pass-rate to the orphan `badges` branch that the
  README badges read.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.github/workflows/conformance-weekly.yaml

@@ -4,13 +4,17 @@ name: conformance-weekly
 # @modelcontextprotocol/conformance release. The on:pull_request pipeline
 # pins to whatever version is available at PR time; this schedule catches
 # upstream releases that add scenarios between PRs.
+#
+# It also scores each run and publishes the client/server pass-rate as
+# shields.io endpoint JSON to the orphan `badges` branch (consumed by the
+# README); that branch is created on the first run.
 on:
   schedule:
     - cron: '0 6 * * 1' # Mondays 06:00 UTC
   workflow_dispatch:
 
 permissions:
-  contents: read
+  contents: write
   issues: write
 
 jobs:
@@ -31,7 +35,10 @@ jobs:
           sleep 5
       - name: Run conformance tests
         working-directory: ./tests/Conformance
-        run: npx --yes @modelcontextprotocol/conformance@latest server --url http://localhost:8000/ --expected-failures conformance-baseline.yml
+        run: npx --yes @modelcontextprotocol/conformance@latest server --url http://localhost:8000/ --expected-failures conformance-baseline.yml --output-dir results
+      - name: Generate score badge
+        if: always()
+        run: php tests/Conformance/score.php server
       - name: Show docker logs on failure
         if: failure()
         run: docker compose -f tests/Conformance/Fixtures/docker-compose.yml logs
@@ -43,6 +50,12 @@ jobs:
           path: |
             tests/Conformance/logs
             tests/Conformance/results
+      - name: Upload score badge
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: server-badge
+          path: tests/Conformance/server-conformance.json
 
   client:
     name: conformance / client (latest)
@@ -60,7 +73,10 @@ jobs:
       - run: mkdir -p tests/Conformance/logs
       - name: Run conformance tests
         working-directory: ./tests/Conformance
-        run: npx --yes @modelcontextprotocol/conformance@latest client --command "php ${{ github.workspace }}/tests/Conformance/client.php" --suite all --expected-failures conformance-baseline.yml
+        run: npx --yes @modelcontextprotocol/conformance@latest client --command "php ${{ github.workspace }}/tests/Conformance/client.php" --suite all --expected-failures conformance-baseline.yml --output-dir results
+      - name: Generate score badge
+        if: always()
+        run: php tests/Conformance/score.php client
       - name: Upload conformance results
         if: failure()
         uses: actions/upload-artifact@v4
@@ -69,6 +85,12 @@ jobs:
           path: |
             tests/Conformance/logs
             tests/Conformance/results
+      - name: Upload score badge
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: client-badge
+          path: tests/Conformance/client-conformance.json
 
   notify:
     name: Open issue on failure
@@ -96,3 +118,45 @@ jobs:
 
           Upstream likely published a release whose scenarios the SDK does not satisfy. Either fix the SDK, update the conformance fixtures, or add the new failure to \`tests/Conformance/conformance-baseline.yml\`."
           fi
+
+  publish:
+    name: Publish conformance badges
+    runs-on: ubuntu-latest
+    needs: [server, client]
+    # Publish even when the suite regressed (the badge should reflect reality);
+    # skip on forks, which cannot push the `badges` branch.
+    if: ${{ !cancelled() && github.repository == 'modelcontextprotocol/php-sdk' }}
+    steps:
+      - uses: actions/checkout@v6
+      - uses: actions/download-artifact@v4
+        with:
+          name: server-badge
+          path: badges-in
+      - uses: actions/download-artifact@v4
+        with:
+          name: client-badge
+          path: badges-in
+      - name: Publish to badges branch
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+
+          if git ls-remote --exit-code --heads origin badges >/dev/null 2>&1; then
+            git fetch origin badges
+            git worktree add badges-wt badges
+          else
+            git worktree add --detach badges-wt
+            git -C badges-wt checkout --orphan badges
+            git -C badges-wt rm -rf --quiet . >/dev/null 2>&1 || true
+          fi
+
+          cp badges-in/server-conformance.json badges-in/client-conformance.json badges-wt/
+
+          cd badges-wt
+          git add -A
+          if git diff --cached --quiet; then
+            echo "Conformance scores unchanged."
+          else
+            git commit -m "Update conformance score badges"
+            git push origin badges
+          fi