* Fix pgsql reader double-quoting defaults: normalizePostgresDefault strips
surrounding SQL string literal quotes from column_default before storing,
matching the convention used by every other reader.
* Add NullableTypes field to WriterOptions with NullableTypeResolveSpec
(default) and NullableTypeStdlib constants.
* Both bun and gorm TypeMappers now accept a typeStyle parameter. stdlib
mode produces sql.NullString/NullInt32/NullTime etc. for nullable scalars,
plain Go slices for arrays, and time.Time for NOT NULL timestamps. Default
resolvespec behaviour is unchanged.
* Add --types flag to convert and split commands.
* Update bun/README.md and gorm/README.md with side-by-side generated code
examples, updated type mapping tables, and Writer Options documentation.
* 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.
- Introduce 'split' command to extract selected tables and schemas.
- Supports various input and output formats.
- Allows filtering of schemas and tables during extraction.
