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/gorm/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"
 )
 
@@ -784,11 +785,14 @@ func (r *Reader) extractGormTag(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.
 	// Also handle precision/scale: numeric(10,2)
 	if strings.Contains(typeStr, "(") {
 		idx := strings.Index(typeStr, "(")
-		baseType = strings.TrimSpace(typeStr[:idx])
+		rawBaseType := strings.TrimSpace(typeStr[:idx])
 
 		// Extract numbers from parentheses
 		parens := typeStr[idx+1:]
@@ -796,14 +800,15 @@ func (r *Reader) parseTypeWithLength(typeStr string) (baseType string, length in
 			parens = parens[:endIdx]
 		}
 
-		// For now, just handle single number (length)
-		if !strings.Contains(parens, ",") {
+		// Only treat as "length" for text-ish SQL types.
+		// This avoids converting custom modifiers like vector(1536) into Length.
+		if pgsql.SupportsLength(rawBaseType) && !strings.Contains(parens, ",") {
 			if _, err := fmt.Sscanf(parens, "%d", &length); err == nil {
 				return
 			}
 		}
 	}
-	baseType = typeStr
+
 	return
 }