fix: readers and linting issues

pkg/readers/gorm/reader.go

@@ -693,7 +693,7 @@ func (r *Reader) deriveTableName(structName string) string {
 
 // parseColumn parses a struct field into a Column model
 // Returns the column and any inline reference information (e.g., "mainaccount(id_mainaccount)")
-func (r *Reader) parseColumn(fieldName string, fieldType ast.Expr, tag string, sequence uint) (*models.Column, string) {
+func (r *Reader) parseColumn(fieldName string, fieldType ast.Expr, tag string, sequence uint) (col *models.Column, ref string) {
 	// Extract gorm tag
 	gormTag := r.extractGormTag(tag)
 	if gormTag == "" {
@@ -756,20 +756,14 @@ func (r *Reader) parseColumn(fieldName string, fieldType ast.Expr, tag string, s
 	// - explicit "not null" tag means NOT NULL
 	// - absence of "not null" tag with sql_types means nullable
 	// - primitive types (string, int64, bool) default to NOT NULL unless explicitly nullable
+	// Primary keys are always NOT NULL
+	column.NotNull = false
 	if _, hasNotNull := parts["not null"]; hasNotNull {
 		column.NotNull = true
 	} else {
-		// If no explicit "not null" tag, check the Go type
-		if r.isNullableGoType(fieldType) {
-			// sql_types.SqlString, etc. are nullable by default
-			column.NotNull = false
-		} else {
-			// Primitive types default to NOT NULL
-			column.NotNull = false // Default to nullable unless explicitly set
-		}
+		// sql_types.SqlString, etc. are nullable by default
+		column.NotNull = !r.isNullableGoType(fieldType)
 	}
-
-	// Primary keys are always NOT NULL
 	if column.IsPrimaryKey {
 		column.NotNull = true
 	}