Transform JSON / JSONB parameter keys

Hey @porsager, hope you're good! 👋 Postgres.js transforms JS property names passed through `sql(...)` helpers, eg. with `{ transform: postgres.camel }`: ```js sql({ firstName: 'Ada' }) // { first_name: 'Ada' } ``` However, currently JSON parameter keys are not transformed 💥 ```js sql.json({ firstName: 'Ada' }) // {"firstName":"Ada"} ``` Maybe this was an oversight in my previous PR for "nested transforms": - #460 This PR adds JSON value transforms before serialization for the built-in case transforms, so JSON and JSONB parameters serialize transformed keys: ```js sql.json({ firstName: 'Ada' }) // {"first_name":"Ada"} ``` This change also applies to JSON / JSONB data created via `sql.typed()` and type casts: ```js sql.typed({ firstName: 'Ada' }, 114) // {"first_name":"Ada"} sql`${ { firstName: 'Ada' } }::jsonb` // {"first_name":"Ada"} ``` - [x] Transform JSON / JSONB parameter keys - [x] Add `value.to` transforms for camel, pascal, and kebab - [x] Test nested objects, arrays, result parsing, and untransformed JSON - [x] Test implicit and typed JSON parameters - [x] Update types AI disclosure: guided use of `gpt-5.5 high` through Codex CLI