ci(release): run tests before publishing

Gate both publish jobs on the package's test suite: npm test
--if-present before the npm build/publish, and pytest (when a tests/
or test/ directory exists, matching python.yml's guard) before the
PyPI build/publish. Previously nothing between tagging and publishing
ran a single test.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AViME1R9ES2UXT1uQDx1TG

.github/workflows/release.yml

@@ -138,6 +138,15 @@ jobs:
         working-directory: src/${{ matrix.package }}
         run: uv run --frozen pyright
 
+      - name: Run tests
+        working-directory: src/${{ matrix.package }}
+        run: |
+          if [ -d "tests" ] || [ -d "test" ]; then
+            uv run pytest
+          else
+            echo "No tests directory, skipping"
+          fi
+
       - name: Build package
         working-directory: src/${{ matrix.package }}
         run: uv build
@@ -189,6 +198,10 @@ jobs:
           fi
           echo "Version $VERSION is new, proceeding with publish"
 
+      - name: Run tests
+        working-directory: src/${{ matrix.package }}
+        run: npm test --if-present
+
       - name: Build package
         working-directory: src/${{ matrix.package }}
         run: npm run build