fix(promo-codes): harden CSV domain import and migration rollback safety

CSV import — blank allowed_email_domains cells produced [''] after
explode, which passed the empty() check on the array but caused
matchesEmailDomain() to reject every email (empty pattern is skipped,
no match found, returns false). Now trims whitespace, filters empty
strings, and unsets the key if no valid domains remain.

Migration down() — replaced DELETE with UPDATE to remap domain-authorized
rows to base types (discount→SummitRegistrationDiscountCode,
promo→SummitRegistrationPromoCode). DELETE would silently cascade through
SummitAttendeeTicket.PromoCodeID (ON DELETE CASCADE), destroying ticket
history. UPDATE preserves FK references while safely narrowing the ENUM.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: caseylocker

app/Services/Model/Imp/SummitPromoCodeService.php

@@ -643,7 +643,10 @@ public function importPromoCodes(Summit $summit, UploadedFile $csv_file, ?Member
                 }
 
                 if(isset($row['allowed_email_domains'])){
-                    $row['allowed_email_domains'] = explode('|', $row['allowed_email_domains']);
+                    $domains = array_map('trim', explode('|', $row['allowed_email_domains']));
+                    $domains = array_values(array_filter($domains, fn($d) => $d !== ''));
+                    $row['allowed_email_domains'] = !empty($domains) ? $domains : null;
+                    if(is_null($row['allowed_email_domains'])) unset($row['allowed_email_domains']);
                 }
 
                 if(isset($row['ticket_types_rules']) && (isset($row['amount']) || isset($row['rate']))){
@@ -750,7 +753,10 @@ public function importSponsorPromoCodes(Summit $summit, UploadedFile $csv_file,
                 }
 
                 if(isset($row['allowed_email_domains'])){
-                    $row['allowed_email_domains'] = explode('|', $row['allowed_email_domains']);
+                    $domains = array_map('trim', explode('|', $row['allowed_email_domains']));
+                    $domains = array_values(array_filter($domains, fn($d) => $d !== ''));
+                    $row['allowed_email_domains'] = !empty($domains) ? $domains : null;
+                    if(is_null($row['allowed_email_domains'])) unset($row['allowed_email_domains']);
                 }
 
                 if(isset($row['ticket_types_rules']) && (isset($row['amount']) || isset($row['rate']))){

database/migrations/model/Version20260401150000.php

@@ -100,11 +100,17 @@ public function down(Schema $schema): void
         $this->addSql("DROP TABLE IF EXISTS DomainAuthorizedSummitRegistrationPromoCode");
         $this->addSql("DROP TABLE IF EXISTS DomainAuthorizedSummitRegistrationDiscountCode");
 
-        // 4b. Delete orphaned base-table rows before narrowing the ENUM
-        $this->addSql("DELETE FROM SummitRegistrationPromoCode WHERE ClassName IN (
-            'DomainAuthorizedSummitRegistrationDiscountCode',
-            'DomainAuthorizedSummitRegistrationPromoCode'
-        )");
+        // 4b. Remap domain-authorized rows to base types to preserve FK references
+        //      (SummitAttendeeTicket.PromoCodeID cascades on delete, so DELETE would destroy ticket history)
+        $this->addSql("UPDATE SummitRegistrationPromoCode
+            SET ClassName = CASE ClassName
+                WHEN 'DomainAuthorizedSummitRegistrationDiscountCode' THEN 'SummitRegistrationDiscountCode'
+                WHEN 'DomainAuthorizedSummitRegistrationPromoCode' THEN 'SummitRegistrationPromoCode'
+            END
+            WHERE ClassName IN (
+                'DomainAuthorizedSummitRegistrationDiscountCode',
+                'DomainAuthorizedSummitRegistrationPromoCode'
+            )");
 
         // 5. Revert the ClassName discriminator ENUM to the original 12 values
         $this->addSql("ALTER TABLE SummitRegistrationPromoCode MODIFY ClassName ENUM(