* 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.
Bun and GORM struct tags now emit quoted defaults for string/date/time/UUID
columns (e.g. default:'disconnected') and unquoted defaults for numeric and
boolean columns (e.g. default:0, default:true). Function-call expressions
such as now() or gen_random_uuid() are never quoted regardless of type.
Adds QuoteDefaultValue(value, sqlType) helper in pkg/writers and updates
both type mappers and the bun writer tests accordingly.
* 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.
* 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.
* Implement SanitizeFilename function to clean identifiers
* Remove quotes, comments, and invalid characters from filenames
* Update filename generation in writers to use sanitized names
