* Implement check constraints in the schema writer.
* Generate SQL statements to add check constraints if they do not exist.
* Add tests to verify correct generation of check constraints.
* Implement unique constraint handling in GenerateSchemaStatements
* Add writeUniqueConstraints method for generating SQL statements
* Create unit test for unique constraints in writer_test.go
* Add functionality to generate ALTER TABLE ADD COLUMN statements for existing tables.
* Introduce tests for generating and writing add column statements.
* Enhance schema evolution capabilities when new columns are added.
* Implement checks for existing primary keys before adding new ones.
* Drop auto-generated primary keys if they exist.
* Add tests for primary key existence and column size specifiers.
* Improve type conversion handling for PostgreSQL compatibility.
* Update script execution to sort by Priority, Sequence, and Name.
* Add functionality to skip symbolic links during directory scanning.
* Improve documentation to reflect changes in execution order and features.
* Add tests for symlink skipping and ensure correct script sorting.
