feat: Registry v2 目录重构 — MCP/HTTP 分离 + install/connection 配置

- 新增 mcp/index.json：MCP 服务独立目录，含 install 和 connection 字段
- 新增 services/index.json：仅 HTTP 服务
- 新增 apps/index.json：应用增加 install 字段
- 新增 models/：descriptors + categories 从 services/ 移出
- 更新 manifest.json：版本升级到 2.0.0，统计拆分 MCP/HTTP
- 更新 SCHEMA_VERSION：1.0.0 → 2.0.0
- 旧文件保留用于向后兼容

新增 7 个 MCP 服务条目（含真实包名和安装命令）：
  - Filesystem MCP (@modelcontextprotocol/server-filesystem)
  - GitHub MCP (@modelcontextprotocol/server-github)
  - Playwright MCP (@playwright/mcp)
  - Dify MCP Bridge
  - Database MCP (@modelcontextprotocol/server-postgres)
  - Memory MCP (@modelcontextprotocol/server-memory)
  - Fetch MCP (mcp-server-fetch, uvx)

services/index.json

@@ -0,0 +1,71 @@
+[
+  {
+    "id": "dify-rag",
+    "name": "Dify RAG API",
+    "description": "Dify 知识库检索服务，支持语义搜索和多知识库联合检索",
+    "protocol": "http",
+    "status": "offline",
+    "origin": "app",
+    "sourceAppId": "dify",
+    "sourceAppName": "Dify",
+    "endpoint": "http://localhost:3000/api/v1/datasets",
+    "capabilities": ["semantic_search", "multi_dataset", "relevance_ranking"],
+    "version": "0.8.3",
+    "author": "Dify.AI",
+    "tags": ["RAG", "知识库", "检索"]
+  },
+  {
+    "id": "ragflow-pipeline",
+    "name": "RagFlow Pipeline",
+    "description": "深度文档理解 RAG 引擎，支持复杂格式文档解析和多级检索",
+    "protocol": "http",
+    "status": "offline",
+    "origin": "app",
+    "sourceAppId": "ragflow",
+    "sourceAppName": "RagFlow",
+    "endpoint": "http://localhost:9380/api/v1",
+    "capabilities": ["doc_parsing", "deep_retrieval", "citation"],
+    "version": "0.14.0",
+    "author": "InfiniFlow",
+    "tags": ["RAG", "文档理解", "Pipeline"]
+  },
+  {
+    "id": "baidu-map",
+    "name": "百度地图 API",
+    "description": "地理位置服务，支持地理编码、路线规划和 POI 搜索",
+    "protocol": "http",
+    "status": "offline",
+    "origin": "manual",
+    "endpoint": "https://api.map.baidu.com/v3",
+    "capabilities": ["geocoding", "route_plan", "poi_search", "distance_calc"],
+    "version": "3.0",
+    "author": "百度",
+    "tags": ["地图", "地理位置", "POI"]
+  },
+  {
+    "id": "deepl-translate",
+    "name": "DeepL 翻译",
+    "description": "高质量多语言翻译服务，支持 30+ 语言互译和文档翻译",
+    "protocol": "http",
+    "status": "offline",
+    "origin": "manual",
+    "endpoint": "https://api-free.deepl.com/v2",
+    "capabilities": ["text_translate", "doc_translate", "language_detect"],
+    "version": "2.0",
+    "author": "DeepL",
+    "tags": ["翻译", "多语言", "NLP"]
+  },
+  {
+    "id": "wecom-webhook",
+    "name": "企业微信 Webhook",
+    "description": "企业微信机器人消息通知，支持文本、Markdown 和卡片消息",
+    "protocol": "http",
+    "status": "offline",
+    "origin": "manual",
+    "endpoint": "https://qyapi.weixin.qq.com/cgi-bin/webhook/send",
+    "capabilities": ["text_message", "markdown_message", "card_message"],
+    "version": "1.0",
+    "author": "腾讯",
+    "tags": ["通知", "企业微信", "Webhook"]
+  }
+]