feat: add record field references to source linking
Add handling for Texp_field in expressions and Tpat_record in patterns.
Record field references (e.g. x.field, { field = ... } patterns) are
linked to their parent type definition by extracting the type path from
the label_description's result type.
Note: Texp_record (record construction expressions) is not yet handled
as individual field locations within record literals require iterating
the fields array. Tpat_record does iterate through fields to link each
field label individually.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>