fix: don't validate insurance selection of participants when in bulk assignment

src/Form/Model/ParticipantDto.php

@@ -105,7 +105,7 @@ class ParticipantDto
     public ?string $licensePlate = null;
 
     // Selected insurance for this participant (individual insurance selection per participant)
-    #[Assert\NotNull(message: 'Bitte auswählen', groups: ['strict_required'])]
+    // Note: Insurance validation is conditional - see ParticipantEditDto::validateInsuranceRequired()
     public ?Insurance $insurance = null;
 
     // Bulk insurance booking flag (applicant only: when checked, assigns same insurance type to all participants)

src/Form/Model/ParticipantEditDto.php

@@ -24,6 +24,56 @@ class ParticipantEditDto
     ) {
     }
 
+    /**
+     * Validates that insurance is selected when required.
+     *
+     * Insurance is required for all participants in create mode, EXCEPT for dependent
+     * participants when the applicant has enabled bulk insurance booking. In that case,
+     * the insurance field is hidden and will be automatically assigned by the bulk
+     * insurance handler.
+     *
+     * This validation only runs when strict_required group is active.
+     */
+    #[Assert\Callback(groups: ['strict_required'])]
+    public function validateInsuranceRequired(ExecutionContextInterface $context): void
+    {
+        // Insurance is always required for applicant
+        if (true === $this->participant->isApplicant()) {
+            if (null === $this->participant->insurance) {
+                $context->buildViolation('Bitte auswählen')
+                    ->atPath('participant.insurance')
+                    ->addViolation();
+            }
+
+            return;
+        }
+
+        // For dependent participants, check if bulk insurance is active
+        $applicant = $this->bookingContext->getParticipant(0);
+        if (null === $applicant) {
+            // Applicant not found - shouldn't happen, but validate insurance to be safe
+            if (null === $this->participant->insurance) {
+                $context->buildViolation('Bitte auswählen')
+                    ->atPath('participant.insurance')
+                    ->addViolation();
+            }
+
+            return;
+        }
+
+        // If bulk insurance booking is active, skip validation (field is hidden, will be auto-assigned)
+        if (true === $applicant->bulkInsuranceBooking) {
+            return;
+        }
+
+        // Bulk insurance not active - insurance is required
+        if (null === $this->participant->insurance) {
+            $context->buildViolation('Bitte auswählen')
+                ->atPath('participant.insurance')
+                ->addViolation();
+        }
+    }
+
     /**
      * Validates that adult participants have unique email addresses.
      *