Replace gorm.io/gen header with gormcol

gen.go

@@ -336,6 +336,11 @@ func (m *GormGen) cleanModelContent(content []byte) []byte {
 	for _, line := range lines {
 		trimmed := strings.TrimSpace(line)
 
+		// Skip gorm.io/gen header comments.
+		if strings.Contains(trimmed, "Code generated by gorm.io/gen") {
+			continue
+		}
+
 		if trimmed == "import (" {
 			importStarted = true
 			newLines = append(newLines, line)
@@ -368,5 +373,11 @@ func (m *GormGen) cleanModelContent(content []byte) []byte {
 	result = strings.Join(newLines, "\n")
 	result = strings.ReplaceAll(result, "psCategoryDo", "")
 
+	// Remove leading empty lines.
+	result = strings.TrimLeft(result, "\n")
+
+	// Add gormcol header comment at the top.
+	result = "// Code generated by gormcol. DO NOT EDIT.\n\n" + result
+
 	return []byte(result)
 }