feat: add props system and refactor asset library architecture

messages/zh/assetLibrary.json

@@ -3,12 +3,15 @@
   "button": "资产库",
   "characters": "角色",
   "locations": "场景",
+  "props": "道具",
   "noCharacters": "暂无角色",
   "noLocations": "暂无场景",
+  "noProps": "暂无道具",
   "addCharacter": "添加角色",
   "addLocation": "添加场景",
+  "addProp": "添加道具",
   "generateImage": "生成图片",
   "regenerateImage": "重新生成",
   "analyzeAssets": "分析资产",
   "analyzing": "分析中..."
-}
+}