Choose one style of accessing records

When I refactored `Type.hs` to use a record as its environment type I used a `-XNamedFieldPuns`-based style to access the fields. Other files already used `-XRecordWildCards` to do the same thing in a different style. We should probably choose one (I prefer the latter but wasn't aware of it before) and stick to it.

Start by comparing the record-field access style in Type.hs with the other Haskell files that use RecordWildCards. Confirm which extensions and access patterns are present across the repository, then standardize the chosen style consistently and verify the project still builds and its existing checks pass.

Written by the indexing model from the issue text.