refactor(modular): 完成第二階段儀表板解耦與模型清理

app/Modules/Core/Services/CoreService.php

@@ -39,4 +39,17 @@ class CoreService implements CoreServiceInterface
     {
         return User::all();
     }
+
+    public function ensureSystemUserExists()
+    {
+        $user = User::first();
+        if (!$user) {
+            $user = User::create([
+                'name' => '系統管理員',
+                'email' => 'admin@example.com',
+                'password' => bcrypt('password'),
+            ]);
+        }
+        return $user;
+    }
 }