[codex] Support PostgreSQL index types in DBML parser

[TheTrustedAdvisor]

Summary

Adds a compatibility layer for DBML indexes that use PostgreSQL index methods currently rejected by @dbml/core, such as gist, gin, brin, and spgist.

Details

@dbml/core rejects DBML index settings like geom_lv95 [type: gist] before this package can transform the parsed schema. The parser currently accepts only btree and hash; this behavior is still present in @dbml/core@8.2.5.

This change normalizes unsupported PostgreSQL index methods to a parser-supported type only inside indexes { ... } blocks, parses the schema, then restores the original index methods on the parsed indexes before validation and transformation.

Validation

• corepack yarn workspace dbml-to-json-table-schema test --runInBand
• Pre-commit hook: lint-staged, including tsc-files --noEmit, eslint --fix, and prettier --write

Notes

A true upstream fix would be to extend the @dbml/core DBML grammar to accept these PostgreSQL index methods directly. Until then, this keeps the workaround local and narrowly scoped.