Make morph maps work with resource syncing

Before, morph maps didn't work because in TriggerSyncingTrait,
we were trying to get the pivot's `$this->morphClass`. Now,
we're first checking if the morph class is an alias, and if it is, resolve
its full class name, if it is not, `$this->morphClass` is already
the class name, so we can use it.

src/ResourceSyncing/TriggerSyncingEvents.php

@@ -9,6 +9,7 @@ use Illuminate\Database\Eloquent\Relations\MorphPivot;
 use Illuminate\Database\Eloquent\Relations\Pivot;
 use Stancl\Tenancy\Contracts\Tenant;
 use Stancl\Tenancy\Database\Contracts\TenantWithDatabase;
+use Illuminate\Database\Eloquent\Relations\Relation;
 
 /**
  * Used on pivot models.
@@ -85,7 +86,7 @@ trait TriggerSyncingEvents
         }
 
         if ($this instanceof MorphPivot) {
-            return $this->morphClass;
+            return Relation::getMorphedModel($this->morphClass) ?? $this->morphClass;
         }
 
         throw new CentralResourceNotAvailableInPivotException;

tests/ResourceSyncingTest.php

@@ -52,6 +52,7 @@ use Stancl\Tenancy\Events\TenantDeleted;
 use Stancl\Tenancy\ResourceSyncing\Events\SyncedResourceDeleted;
 use Stancl\Tenancy\ResourceSyncing\Listeners\DeleteAllTenantMappings;
 use Stancl\Tenancy\ResourceSyncing\Listeners\DeleteResourceMapping;
+use Illuminate\Database\Eloquent\Relations\Relation;
 
 beforeEach(function () {
     config(['tenancy.bootstrappers' => [
@@ -1364,6 +1365,49 @@ test('global scopes on syncable models can break resource syncing', function ()
     expect($tenant1->run(fn () => TenantUser::first()->name))->toBe('tenant2 user');
 });
 
+test('attach and detach events are handled correctly when using morph maps', function() {
+    config(['tenancy.models.tenant' => MorphTenant::class]);
+    [$tenant] = createTenantsAndRunMigrations();
+    migrateCompaniesTableForTenants();
+
+    Relation::morphMap([
+        'users' => BaseCentralUser::class,
+        'companies' => CentralCompany::class,
+    ]);
+
+    $centralUser = BaseCentralUser::create([
+        'global_id' => 'user',
+        'name' => 'Central user',
+        'email' => 'central@localhost',
+        'password' => 'password',
+        'role' => 'user',
+    ]);
+
+    $centralCompany = CentralCompany::create([
+        'global_id' => 'company',
+        'name' => 'Central company',
+        'email' => 'company@localhost',
+    ]);
+
+    $tenant->users()->attach($centralUser);
+    $tenant->companies()->attach($centralCompany);
+
+    tenancy()->initialize($tenant);
+
+    expect(BaseTenantUser::whereGlobalId('user')->first())->not()->toBeNull();
+    expect(TenantCompany::whereGlobalId('company')->first())->not()->toBeNull();
+
+    tenancy()->end();
+
+    $tenant->users()->detach($centralUser);
+    $tenant->companies()->detach($centralCompany);
+
+    tenancy()->initialize($tenant);
+
+    expect(BaseTenantUser::whereGlobalId('user')->first())->toBeNull();
+    expect(TenantCompany::whereGlobalId('company')->first())->toBeNull();
+});
+
 function addTenantIdConstraintToPivot(string $pivotTable): void
 {
     Schema::table($pivotTable, function (Blueprint $table) {