Fix null coalescing for empty config fields

- Use ?: instead of ?? in EggTransformer so empty strings also fall back to '{}'
- Apply same null-safety to config_startup and config_logs json_decode calls
- Replace ineffective default('{}') with dehydrateStateUsing on EditEgg form

app/Filament/Admin/Resources/Eggs/Pages/EditEgg.php

@@ -318,6 +318,7 @@ class EditEgg extends EditRecord
                         ->helperText(trans('admin/egg.start_config_help')),
                     Textarea::make('config_files')->rows(10)->json()
                         ->label(trans('admin/egg.config_files'))
+                        ->dehydrateStateUsing(fn ($state) => blank($state) ? '{}' : $state)
                         ->helperText(trans('admin/egg.config_files_help')),
                     Textarea::make('config_logs')->rows(10)->json()
                         ->label(trans('admin/egg.log_config'))

app/Services/Eggs/EggConfigurationService.php

@@ -32,10 +32,10 @@ class EggConfigurationService
      */
     public function handle(Server $server): array
     {
-        $configs = $this->replacePlaceholders(
-            $server,
-            json_decode($server->egg->inherit_config_files)
-        );
+        $configFiles = json_decode($server->egg->inherit_config_files ?? '{}');
+        $configs = is_object($configFiles) || is_array($configFiles)
+            ? $this->replacePlaceholders($server, $configFiles)
+            : [];
 
         return [
             'startup' => $this->convertStartupToNewFormat(json_decode($server->egg->inherit_config_startup, true)),

app/Transformers/Api/Application/EggTransformer.php

@@ -36,7 +36,7 @@ class EggTransformer extends BaseTransformer
     {
         $model->loadMissing('configFrom');
 
-        $files = json_decode($model->inherit_config_files, true, 512, JSON_THROW_ON_ERROR);
+        $files = json_decode($model->inherit_config_files ?: '{}', true, 512, JSON_THROW_ON_ERROR);
 
         $model->loadMissing('scriptFrom');
 
@@ -53,9 +53,9 @@ class EggTransformer extends BaseTransformer
             'docker_images' => $model->docker_images,
             'config' => [
                 'files' => $files,
-                'startup' => json_decode($model->inherit_config_startup, true),
+                'startup' => json_decode($model->inherit_config_startup ?: '{}', true),
                 'stop' => $model->inherit_config_stop,
-                'logs' => json_decode($model->inherit_config_logs, true),
+                'logs' => json_decode($model->inherit_config_logs ?: '{}', true),
                 'file_denylist' => $model->inherit_file_denylist,
                 'extends' => $model->config_from,
             ],