* 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.
* Update model name generation to include schema name.
* Add gofmt execution after writing output files.
* Refactor relationship field naming to include schema.
* Update tests to reflect changes in model names and relationships.
* Implement field name collision resolution in model generation.
* Add tests to verify renaming of fields that conflict with generated method names.
* Ensure primary key type safety in UpdateID method.
* Implement SanitizeStructTagValue function to clean identifiers for struct tags.
* Update model data generation to use sanitized column names.
* Ensure safe handling of backticks in column names and types across writers.
