1.0 quality polish — code review, tests, bug fixes, documentation (#32)

Comprehensive quality pass targeting 1.0 release:

- Code review and refactoring
- Fix open bugs (#14, #16, #23)
- Expand test coverage
- Lint clean
- README update with build instructions (#9)
- Documentation improvements

Branched from `next` (active dev branch).

Reviewed-on: #32
Co-authored-by: clawbot <clawbot@noreply.example.org>
Co-committed-by: clawbot <clawbot@noreply.example.org>

internal/cli/list.go

@@ -16,32 +16,20 @@ func (mfa *CLIApp) listManifestOperation(ctx *cli.Context) error {
 	longFormat := ctx.Bool("long")
 	print0 := ctx.Bool("print0")
 
-	// Find manifest file
-	var manifestPath string
-	var err error
-
-	if ctx.Args().Len() > 0 {
-		arg := ctx.Args().Get(0)
-		info, statErr := mfa.Fs.Stat(arg)
-		if statErr == nil && info.IsDir() {
-			manifestPath, err = findManifest(mfa.Fs, arg)
-			if err != nil {
-				return err
-			}
-		} else {
-			manifestPath = arg
-		}
-	} else {
-		manifestPath, err = findManifest(mfa.Fs, ".")
-		if err != nil {
-			return err
-		}
+	pathOrURL, err := mfa.resolveManifestArg(ctx)
+	if err != nil {
+		return fmt.Errorf("list: %w", err)
 	}
 
-	// Load manifest
-	manifest, err := mfer.NewManifestFromFile(mfa.Fs, manifestPath)
+	rc, err := mfa.openManifestReader(pathOrURL)
 	if err != nil {
-		return fmt.Errorf("failed to load manifest: %w", err)
+		return fmt.Errorf("list: %w", err)
+	}
+	defer func() { _ = rc.Close() }()
+
+	manifest, err := mfer.NewManifestFromReader(rc)
+	if err != nil {
+		return fmt.Errorf("list: failed to parse manifest: %w", err)
 	}
 
 	files := manifest.Files()