feat(exiftool): handle boolean metadata

pkg/modules/exiftool/exiftool.go

@@ -107,6 +107,10 @@ func (engine *ExifTool) WriteMetadata(ctx context.Context, logger *zap.Logger, m
 		switch val := value.(type) {
 		case string:
 			fileMetadata[0].SetString(key, val)
+		case []string:
+			fileMetadata[0].SetStrings(key, val)
+		case bool:
+			fileMetadata[0].SetString(key, fmt.Sprintf("%t", val))
 		case int:
 			fileMetadata[0].SetInt(key, int64(val))
 		case int64:
@@ -115,8 +119,6 @@ func (engine *ExifTool) WriteMetadata(ctx context.Context, logger *zap.Logger, m
 			fileMetadata[0].SetFloat(key, float64(val))
 		case float64:
 			fileMetadata[0].SetFloat(key, val)
-		case []string:
-			fileMetadata[0].SetStrings(key, val)
 		// TODO: support more complex cases, e.g., arrays and nested objects
 		// 	(limitations in underlying library).
 		default:

pkg/modules/exiftool/exiftool_test.go

@@ -184,7 +184,7 @@ func TestExiftool_WriteMetadata(t *testing.T) {
 					"first",
 					"second",
 				},
-				"Marked":     "true",
+				"Marked":     true,
 				"ModDate":    "2006-09-18T16:27:50-04:00",
 				"PDFVersion": 1.7,
 				"Producer":   "Gotenberg",