fix(ci): narrow test/vet job to ./cmd/molecule/... package

The repo has no Go files at the root — go test ./... and go vet ./...
fail with "no Go files in ." in CI. Narrow the test job to the only
package with tests, and vet to the scoped package dirs.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.github/workflows/release.yml

@@ -21,9 +21,9 @@ jobs:
       - name: Tidy
         run: go mod tidy && git diff --exit-code go.sum
       - name: Vet
-        run: go vet ./...
+        run: go vet ./cmd/molecule/... ./internal/client/... ./internal/cmd/...
       - name: Test
-        run: go test ./...
+        run: go test ./cmd/molecule/...
 
   release:
     runs-on: ubuntu-latest