feat(relations): 🎉 add flatten schema option for output

* Introduce `--flatten-schema` flag to convert, merge, and split commands.
* Modify database writing functions to support flattened schema names.
* Update template functions to handle schema.table naming convention.
* Enhance PostgreSQL writer to utilize flattened schema in generated SQL.
* Update tests to ensure compatibility with new flattening feature.
* Dependencies updated for improved functionality.

pkg/writers/gorm/writer.go

@@ -83,7 +83,7 @@ func (w *Writer) writeSingleFile(db *models.Database) error {
 	// Collect all models
 	for _, schema := range db.Schemas {
 		for _, table := range schema.Tables {
-			modelData := NewModelData(table, schema.Name, w.typeMapper)
+			modelData := NewModelData(table, schema.Name, w.typeMapper, w.options.FlattenSchema)
 
 			// Add relationship fields
 			w.addRelationshipFields(modelData, table, schema, db)
@@ -175,7 +175,7 @@ func (w *Writer) writeMultiFile(db *models.Database) error {
 			templateData.AddImport(fmt.Sprintf("sql_types \"%s\"", w.typeMapper.GetSQLTypesImport()))
 
 			// Create model data
-			modelData := NewModelData(table, schema.Name, w.typeMapper)
+			modelData := NewModelData(table, schema.Name, w.typeMapper, w.options.FlattenSchema)
 
 			// Add relationship fields
 			w.addRelationshipFields(modelData, table, schema, db)