feat: log plugin runtime errors

exec/handlers/update.php

@@ -19,6 +19,7 @@ return static function (AppContext $ctx): void {
             $ctx->syncActiveBackend();
             Http::redirect($ctx->url('index.html', ['status' => 'updated']));
         } catch (Throwable $e) {
+            PluginLogger::exception($e, 'UPDATE');
             $errors[] = $e->getMessage();
         }
     }