Add ESM-aware types for pgvector/kysely

[briandastous]

Summary

• add ESM-aware type declarations for pgvector/kysely via index.d.mts
• wire exports["./kysely"].types.import to the new ESM declarations

Rationale

TypeScript NodeNext treats pgvector as CJS, so pgvector/kysely currently resolves kysely types via the CJS path. ESM consumers resolve kysely via the ESM path, which makes RawBuilder incompatible. Providing an ESM .d.mts and an import types condition aligns the types for ESM users.

Fixes #29.

Testing

• not run (type-only change)