wip: modernized edit flow, fix insurance tier calculation

src/Form/Service/ParticipantInsuranceFieldHandler.php

@@ -125,6 +125,10 @@ class ParticipantInsuranceFieldHandler extends AbstractParticipantFieldHandler
         $currentInsurance = $participant->insurance;
         $availableInsurances = $bookingDto->travel->insurances ?? [];
 
+        // Exclude complementary insurances from reassignment logic
+        // They are only available as part of packages and cannot be directly selected
+        $availableInsurances = array_filter($availableInsurances, fn ($insurance) => !$insurance->complementary);
+
         // Determine if this is a new user selection or just form resubmission
         $isNewSelection = null !== $selectedInsuranceId
             && (null === $currentInsurance || !$this->isSameInsurance($selectedInsuranceId, $currentInsurance));