refactor: icon 字段从 Lucide 名称迁移到内联 SVG

将 9 个技能的 icon 字段从 Lucide 图标名称（如 "search"）替换为
内联 SVG 字符串，使市场数据完全自包含，新增技能无需修改前端代码。

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

skills/email-client/skill.json

@@ -1,11 +1,17 @@
 {
   "id": "email-client",
   "name": "邮件助理",
-  "icon": "mail",
+  "icon": "<svg xmlns=\"http://www.w3.org/2000/svg\" width=\"24\" height=\"24\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"m22 7-8.991 5.727a2 2 0 0 1-2.009 0L2 7\"></path><rect x=\"2\" y=\"4\" width=\"20\" height=\"16\" rx=\"2\"></rect></svg>",
   "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"],
+  "tags": [
+    "邮件",
+    "收件箱管理",
+    "自动回复",
+    "跟进提醒",
+    "通讯"
+  ],
   "version": "2.2.0",
   "latestVersion": "2.2.0",
   "updatedAt": "2025-02-11",
@@ -19,9 +25,23 @@
   "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"],
+  "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"
 }