refactor: 清理废弃字段，同步 Schema 定义

- Agent 文件：删除 downloads、rating、ratingCount、installStatus、source
- Skill 文件：删除 downloads、rating、ratingCount、installStatus、source、version
- Skill 文件：新增 files 字段，指向配置文件路径
- 字段说明：source 和 installStatus 改为运行时计算

Refs: desirecore/desirecore#field-recovery

skills/web-search/skill.json

@@ -5,23 +5,39 @@
   "shortDesc": "智能网络搜索与信息聚合，快速获取准确答案",
   "fullDesc": "网络搜索技能让 Agent 能够实时检索互联网信息，支持多引擎聚合、结果去重、可信度评估和结构化摘要。不只是返回链接，而是提炼出可直接使用的答案。\n\n功能特性：\n- 多引擎聚合：Google、Bing、DuckDuckGo 结果综合\n- 智能摘要：自动提取关键信息，生成 TL;DR\n- 可信度评估：基于域名权威性、发布日期、交叉验证打分\n- 实时热点：追踪新闻、社交媒体趋势\n- 学术搜索：arXiv、Google Scholar、PubMed 专精模式",
   "category": "productivity",
-  "tags": ["搜索", "信息检索", "网页抓取", "实时信息", "研究辅助"],
-  "version": "3.0.2",
+  "tags": [
+    "搜索",
+    "信息检索",
+    "网页抓取",
+    "实时信息",
+    "研究辅助"
+  ],
   "latestVersion": "3.0.2",
   "updatedAt": "2025-02-10",
   "maintainer": {
     "name": "DesireCore Official",
     "verified": true
   },
-  "downloads": 89340,
-  "rating": 4.8,
-  "ratingCount": 3421,
-  "installStatus": "not_installed",
   "riskLevel": "medium",
   "requires": {
-    "tools": ["http_client", "html_parser", "rate_limiter"],
-    "connections": ["internet", "search_api"]
+    "tools": [
+      "http_client",
+      "html_parser",
+      "rate_limiter"
+    ],
+    "connections": [
+      "internet",
+      "search_api"
+    ]
   },
-  "compatibleAgents": ["translator", "business-analyst", "data-analyst", "writing-coach"],
-  "changelog": "v3.0.2: 新增 AI 搜索结果去重算法，减少 40% 冗余信息"
+  "compatibleAgents": [
+    "translator",
+    "business-analyst",
+    "data-analyst",
+    "writing-coach"
+  ],
+  "changelog": "v3.0.2: 新增 AI 搜索结果去重算法，减少 40% 冗余信息",
+  "files": {
+    "config": "skills/web-search/skill.json"
+  }
 }