The unique constraint on cvMatcher.Results was defined as (CvDocumentId, JobDocumentId)
but the code checks for (CvDocumentId, JobDocumentId, Language). This mismatch caused
duplicate key violations when matching the same CV+Job in different languages.
Update the constraint to (CvDocumentId, JobDocumentId, Language) to allow different
languages for the same CV+Job pair while preventing true duplicates.
Resolves: Duplicate key constraint violations on concurrent/repeated match requests