add holiday test and tweak services

backend/handlers/scheduling/default-hours.go

@@ -318,7 +318,15 @@ func GetAvailableHours(w http.ResponseWriter, r *http.Request) {
 
 	// Load bookings
 	bookingRows, _ := db.DB.Query(r.Context(), `
-		SELECT b.start_time, COALESCE(SUM(s.duration_minutes),0) as total_duration
+		SELECT 
+			b.start_time, 
+			COALESCE(SUM(
+				CASE 
+					WHEN bs.override_duration_minutes IS NOT NULL AND bs.override_duration_minutes > 0 
+						THEN bs.override_duration_minutes 
+					ELSE s.duration_minutes 
+				END
+			), 0) AS total_duration
 		FROM bookings b
 		LEFT JOIN booking_services bs ON b.id = bs.booking_id
 		LEFT JOIN services s ON bs.service_id = s.id