feat: person identity matching with detection, confirmation and audit trail

Implements enterprise-grade identity resolution (detect → suggest → confirm)
for Person ↔ User linking. Matches are detected automatically on person
creation and user account creation, then surfaced to organisers for explicit
confirmation or dismissal. No silent auto-linking.

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

api/app/Http/Controllers/Api/V1/PersonController.php

@@ -11,17 +11,22 @@ use App\Http\Resources\Api\V1\PersonCollection;
 use App\Http\Resources\Api\V1\PersonResource;
 use App\Models\Event;
 use App\Models\Person;
+use App\Services\PersonIdentityService;
 use Illuminate\Http\JsonResponse;
 use Illuminate\Http\Request;
 use Illuminate\Support\Facades\Gate;
 
 final class PersonController extends Controller
 {
+    public function __construct(
+        private readonly PersonIdentityService $identityService,
+    ) {}
+
     public function index(Request $request, Event $event): PersonCollection
     {
         Gate::authorize('viewAny', [Person::class, $event]);
 
-        $query = $event->persons()->with('crowdType');
+        $query = $event->persons()->with(['crowdType', 'pendingIdentityMatch.matchedUser']);
 
         if ($request->filled('crowd_type_id')) {
             $query->where('crowd_type_id', $request->input('crowd_type_id'));
@@ -72,6 +77,8 @@ final class PersonController extends Controller
 
         $person = $event->persons()->create($request->validated());
 
+        $this->identityService->detectMatchForPerson($person);
+
         return $this->created(new PersonResource($person->fresh()->load('crowdType')));
     }