Return all matches in search/

For the sake of keeping the 3 normalizer responses consistent:

- Return all matches for a query. If different match types point to same record, use the highest match type
- Add match_type to Therapy class

Start in the search/ implementation and inspect the three normalizer responses, then locate the Therapy class. Confirm how match types currently map to records and what response shape is shared. Done means queries return all distinct matching records, duplicate records keep the highest match type, and Therapy exposes match_type.

Written by the indexing model from the issue text.