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/email-client/skill.json

@@ -5,23 +5,41 @@
   "shortDesc": "智能邮件管理，自动分类、起草与跟进提醒",
   "fullDesc": "邮件助理帮助 Agent 安全地访问你的邮箱，执行智能分类、优先级排序、自动回复起草和跟进提醒。支持 Gmail、Outlook、企业 Exchange 和 IMAP 协议，所有操作需经用户确认。\n\n功能特性：\n- 统一收件箱：多账户聚合、智能分类（工作/社交/推广/垃圾）\n- 智能起草：根据上下文生成得体回复、多语气选择\n- 跟进管理：自动识别待回复邮件、设置跟进提醒\n- 摘要功能：长邮件线程 TL;DR、每日收件箱总结\n- 安全控制：敏感操作确认、发送前预览、撤销窗口",
   "category": "communication",
-  "tags": ["邮件", "收件箱管理", "自动回复", "跟进提醒", "通讯"],
-  "version": "2.2.0",
+  "tags": [
+    "邮件",
+    "收件箱管理",
+    "自动回复",
+    "跟进提醒",
+    "通讯"
+  ],
   "latestVersion": "2.2.0",
   "updatedAt": "2025-02-11",
   "maintainer": {
     "name": "DesireCore Official",
     "verified": true
   },
-  "downloads": 52180,
-  "rating": 4.6,
-  "ratingCount": 2134,
-  "installStatus": "not_installed",
   "riskLevel": "high",
   "requires": {
-    "tools": ["imap_client", "smtp_client", "oauth_client", "pgp_encryption"],
-    "connections": ["gmail_api", "outlook_api", "exchange_server"]
+    "tools": [
+      "imap_client",
+      "smtp_client",
+      "oauth_client",
+      "pgp_encryption"
+    ],
+    "connections": [
+      "gmail_api",
+      "outlook_api",
+      "exchange_server"
+    ]
   },
-  "compatibleAgents": ["translator", "business-analyst", "writing-coach", "task-master"],
-  "changelog": "v2.2.0: 新增邮件情绪分析，自动标记紧急和负面语气邮件"
+  "compatibleAgents": [
+    "translator",
+    "business-analyst",
+    "writing-coach",
+    "task-master"
+  ],
+  "changelog": "v2.2.0: 新增邮件情绪分析，自动标记紧急和负面语气邮件",
+  "files": {
+    "config": "skills/email-client/skill.json"
+  }
 }