feat(index): implement GIN index support for quoted text columns and enhance index column resolution

pkg/writers/pgsql/writer.go

@@ -261,7 +261,7 @@ func (w *Writer) GenerateSchemaStatements(schema *models.Schema) ([]string, erro
 			columnExprs := make([]string, 0, len(index.Columns))
 			for _, colName := range index.Columns {
 				colExpr := colName
-				if col, ok := table.Columns[colName]; ok {
+				if col, ok := resolveIndexColumn(table, colName); ok {
 					// For GIN indexes on text columns, add operator class
 					if strings.EqualFold(indexType, "gin") && isTextType(col.Type) {
 						opClass := extractOperatorClass(index.Comment)
@@ -855,7 +855,7 @@ func (w *Writer) writeIndexes(schema *models.Schema) error {
 			// Build column list with operator class support for GIN indexes
 			columnExprs := make([]string, 0, len(index.Columns))
 			for _, colName := range index.Columns {
-				if col, ok := table.Columns[colName]; ok {
+				if col, ok := resolveIndexColumn(table, colName); ok {
 					colExpr := col.SQLName()
 					// For GIN indexes on text columns, add operator class
 					if strings.EqualFold(index.Type, "gin") && isTextType(col.Type) {
@@ -1269,6 +1269,33 @@ func isTextTypeWithoutLength(colType string) bool {
 	return strings.EqualFold(colType, "text")
 }
 
+func resolveIndexColumn(table *models.Table, colName string) (*models.Column, bool) {
+	if table == nil {
+		return nil, false
+	}
+	if col, ok := table.Columns[colName]; ok && col != nil {
+		return col, true
+	}
+
+	normalized := strings.ToLower(strings.Trim(colName, `"`))
+	for key, col := range table.Columns {
+		if col == nil {
+			continue
+		}
+		if strings.ToLower(strings.Trim(key, `"`)) == normalized {
+			return col, true
+		}
+		if strings.ToLower(strings.Trim(col.Name, `"`)) == normalized {
+			return col, true
+		}
+		if strings.ToLower(strings.Trim(col.SQLName(), `"`)) == normalized {
+			return col, true
+		}
+	}
+
+	return nil, false
+}
+
 // formatStringList formats a list of strings as a SQL-safe comma-separated quoted list
 func formatStringList(items []string) string {
 	quoted := make([]string, len(items))