Add golangci-lint to CI with minimal config.

Enforce standard linters in GitHub Actions and fix unchecked Close calls flagged by errcheck.

Author: armanfeyzi

.github/workflows/ci.yml

@@ -34,6 +34,11 @@ jobs:
       - name: Go vet
         run: go vet ./...
 
+      - name: Run golangci-lint
+        uses: golangci/golangci-lint-action@v9
+        with:
+          version: v2.12
+
       - name: Build Linux amd64 binary
         run: |
           mkdir -p dist

.golangci.yml

@@ -0,0 +1,7 @@
+version: "2"
+
+linters:
+  default: standard
+
+run:
+  timeout: 5m

internal/catalog/builder.go

@@ -363,7 +363,7 @@ func decodeHelmRelease(data []byte) ([]byte, error) {
 	if err != nil {
 		return nil, err
 	}
-	defer gr.Close()
+	defer func() { _ = gr.Close() }()
 
 	decoded, err := io.ReadAll(gr)
 	if err != nil {

internal/resolver/oci_resolver.go

@@ -310,7 +310,7 @@ func (r *OCIResolver) negotiateBearerToken(ctx context.Context, wwwAuthenticate,
 	if err != nil {
 		return "", fmt.Errorf("fetch oci token: %w", err)
 	}
-	defer tokResp.Body.Close()
+	defer func() { _ = tokResp.Body.Close() }()
 
 	if tokResp.StatusCode != http.StatusOK {
 		return "", fmt.Errorf("oci token status: %s", tokResp.Status)

internal/resolver/repository_resolver.go

@@ -96,7 +96,7 @@ func (r *RepositoryResolver) RefreshRepoIndex(ctx context.Context, repoURL strin
 	if err != nil {
 		return model.RepoCacheEntry{}, fmt.Errorf("fetch index.yaml: %w", err)
 	}
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	if resp.StatusCode != http.StatusOK {
 		return model.RepoCacheEntry{}, fmt.Errorf("fetch index.yaml status: %s", resp.Status)