test(drawdb): add test for converting column types with modifiers

* Implement tests to ensure explicit type modifiers are preserved during conversion.
* Validate behavior for varchar, numeric, and custom vector types.

pkg/readers/bun/reader.go

@@ -12,6 +12,7 @@ import (
 	"strings"
 
 	"git.warky.dev/wdevs/relspecgo/pkg/models"
+	"git.warky.dev/wdevs/relspecgo/pkg/pgsql"
 	"git.warky.dev/wdevs/relspecgo/pkg/readers"
 )
 
@@ -700,16 +701,21 @@ func (r *Reader) extractBunTag(tag string) string {
 // parseTypeWithLength parses a type string and extracts length if present
 // e.g., "varchar(255)" returns ("varchar", 255)
 func (r *Reader) parseTypeWithLength(typeStr string) (baseType string, length int) {
+	typeStr = strings.TrimSpace(typeStr)
+	baseType = typeStr
+
 	// Check for type with length: varchar(255), char(10), etc.
 	re := regexp.MustCompile(`^([a-zA-Z\s]+)\((\d+)\)$`)
 	matches := re.FindStringSubmatch(typeStr)
 	if len(matches) == 3 {
-		if _, err := fmt.Sscanf(matches[2], "%d", &length); err == nil {
-			baseType = strings.TrimSpace(matches[1])
-			return
+		rawBaseType := strings.TrimSpace(matches[1])
+		if pgsql.SupportsLength(rawBaseType) {
+			if _, err := fmt.Sscanf(matches[2], "%d", &length); err == nil {
+				return
+			}
 		}
 	}
-	baseType = typeStr
+
 	return
 }