S2a: purge legacy Form Builder PHP code and routes

api/app/Services/PersonIdentityService.php

@@ -357,9 +357,6 @@ final class PersonIdentityService
                 ]);
         });
 
-        // Sync registration tags
-        $this->syncRegistrationTags($person);
-
         activity('identity')
             ->causedBy($resolvedBy)
             ->performedOn($person)
@@ -498,9 +495,6 @@ final class PersonIdentityService
                 ]);
         });
 
-        // Sync registration tags
-        $this->syncRegistrationTags($person);
-
         activity('identity')
             ->causedBy($linkedBy)
             ->performedOn($person)
@@ -550,23 +544,4 @@ final class PersonIdentityService
         return $person->fresh();
     }
 
-    /**
-     * Sync registration tags when identity is confirmed.
-     */
-    private function syncRegistrationTags(Person $person): void
-    {
-        if ($person->user_id === null) {
-            return;
-        }
-
-        try {
-            app(TagSyncService::class)->syncFromRegistration($person);
-        } catch (\Exception $e) {
-            Log::warning('Failed to sync registration tags on identity confirm', [
-                'person_id' => $person->id,
-                'user_id' => $person->user_id,
-                'error' => $e->getMessage(),
-            ]);
-        }
-    }
 }