修复删除策略或删除组导致500错误的bug

app/Http/Controllers/Admin/StrategyController.php

@@ -59,8 +59,12 @@ class StrategyController extends Controller
 
     public function delete(Request $request): Response
     {
-        if ($group = Strategy::query()->find($request->route('id'))) {
-            $group->delete();
+        /** @var Strategy $strategy */
+        if ($strategy = Strategy::query()->find($request->route('id'))) {
+            DB::transaction(function () use ($strategy) {
+                $strategy->images()->update(['strategy_id' => null]);
+                $strategy->delete();
+            });
         }
         return $this->success('删除成功');
     }

app/Models/Image.php

@@ -169,10 +169,10 @@ class Image extends Model
     {
         return new Attribute(function () {
             // 是否启用原图保护功能
-            if ($this->group->configs->get(GroupConfigKey::IsEnableOriginalProtection)) {
+            if ($this->group?->configs->get(GroupConfigKey::IsEnableOriginalProtection)) {
                 return asset("{$this->key}.{$this->extension}");
             } else {
-                return rtrim($this->strategy->configs->get('url'), '/').'/'.$this->pathname;
+                return rtrim($this->strategy?->configs->get('url'), '/').'/'.$this->pathname;
             }
         });
     }