refactor(cli): drop checks no outcome depends on

Mutation testing showed these edits change nothing a caller sees:
skipJSONValue only meets opening delimiters at a value's position and
can consume an object's keys like its values; orderedObjectKeys' empty
input already fails the first token; ociAnnotationID's missing or empty
annotation already fails to unmarshal; filepath.Localize only returns
local paths, so the IsLocal check after it refuses nothing; every
caller of downloadFeatureTarball passes a context; and the replacer's
capacity hint is unobservable. The 512 MiB download cap is exempt, as
only a 512 MiB response could show it move.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: aledbf

internal/cli/collection_commands.go

@@ -599,7 +599,7 @@ func generateDocs(projectFolder, registry, namespace, githubOwner, githubRepo, c
 }
 
 func renderDocsTemplate(template string, values map[string]string) string {
-	pairs := make([]string, 0, len(values)*2)
+	var pairs []string
 	for name, value := range values {
 		pairs = append(pairs, "#{"+name+"}", value)
 	}
@@ -707,15 +707,9 @@ func defaultCell(ov map[string]any) string {
 
 // orderedObjectKeys returns the keys of a JSON object in source order.
 func orderedObjectKeys(raw json.RawMessage) []string {
-	if len(raw) == 0 {
-		return nil
-	}
 	dec := json.NewDecoder(bytes.NewReader(raw))
 	t, err := dec.Token()
-	if err != nil {
-		return nil
-	}
-	if d, ok := t.(json.Delim); !ok || d != '{' {
+	if err != nil || t != json.Delim('{') {
 		return nil
 	}
 	var keys []string
@@ -734,27 +728,24 @@ func orderedObjectKeys(raw json.RawMessage) []string {
 	return keys
 }
 
+// skipJSONValue consumes the next value from dec. At a value's position the
+// decoder only ever yields an opening delimiter, so any Delim starts a
+// container; an object's keys are string tokens, consumed like its values.
 func skipJSONValue(dec *json.Decoder) error {
 	t, err := dec.Token()
 	if err != nil {
 		return err
 	}
-	if d, ok := t.(json.Delim); ok && (d == '{' || d == '[') {
-		for dec.More() {
-			if d == '{' {
-				if _, err := dec.Token(); err != nil { // key
-					return err
-				}
-			}
-			if err := skipJSONValue(dec); err != nil {
-				return err
-			}
-		}
-		if _, err := dec.Token(); err != nil { // closing delim
+	if _, ok := t.(json.Delim); !ok {
+		return nil
+	}
+	for dec.More() {
+		if err := skipJSONValue(dec); err != nil {
 			return err
 		}
 	}
-	return nil
+	_, err = dec.Token() // closing delim
+	return err
 }
 
 // createTarArchive creates a plain (uncompressed) tar archive from a directory,

internal/cli/feature_deps.go

@@ -163,14 +163,14 @@ func featureMetadataFromTarball(blob []byte) (features.Feature, error) {
 	return meta, nil
 }
 
+// ociAnnotationID is the id in the manifest's metadata annotation, or "" when
+// the annotation is missing, empty or not JSON (none of which unmarshal).
 func ociAnnotationID(manifest *oci.ManifestContainer) string {
-	if mj, ok := manifest.Manifest.Annotations["dev.containers.metadata"]; ok && mj != "" {
-		var meta features.Feature
-		if json.Unmarshal([]byte(mj), &meta) == nil {
-			return meta.ID
-		}
+	var meta features.Feature
+	if json.Unmarshal([]byte(manifest.Manifest.Annotations["dev.containers.metadata"]), &meta) != nil {
+		return ""
 	}
-	return ""
+	return meta.ID
 }
 
 func readLocalFeatureMetadata(dir string) (features.Feature, error) {

internal/cli/feature_install.go

@@ -912,11 +912,12 @@ func extractTarGz(archivePath, destDir string) error {
 
 		// Tar paths always use forward slashes. Localize rejects absolute paths,
 		// parent traversal, and names that cannot be represented safely on the
-		// current platform. Root also prevents escapes through symlinks already
-		// present below destDir.
+		// current platform; what it returns is always local, as filepath.IsLocal
+		// reports. Root also prevents escapes through symlinks already present
+		// below destDir.
 		cleanName := path.Clean(header.Name)
 		localName, err := filepath.Localize(cleanName)
-		if err != nil || !filepath.IsLocal(localName) {
+		if err != nil {
 			return fmt.Errorf("tar entry %q escapes the destination directory", header.Name)
 		}
 
@@ -992,9 +993,6 @@ func (e *digestMismatchError) Error() string {
 // It returns the tarball bytes and their computed "sha256:<hex>" digest so the
 // caller can pin/verify integrity (TS records and checks this digest).
 func downloadFeatureTarball(ctx context.Context, logger log.Logger, tarballURL string, env map[string]string) ([]byte, string, error) {
-	if ctx == nil {
-		ctx = context.Background()
-	}
 	req, err := http.NewRequestWithContext(ctx, http.MethodGet, tarballURL, nil)
 	if err != nil {
 		return nil, "", err