Full-text search across BOTH outbound and incoming calls in one query. Matches against transcripts, finalSummary, title, phoneNumber/phoneNumberFrom, goal, and callerName (case-insensitive). Results carry a callType: 'outgoing' | 'incoming' discriminator plus matchedFields showing which columns hit. For outbound-only results use /calls/search/outgoing; for incoming-only use /incoming-calls/search. Soft-deleted calls are excluded.