feat: 新增 HTTP MCP Server，让 AI Agent 接入选菜

新增 packages/mcp，基于 Streamable HTTP 暴露菜谱库能力，复用 packages/cook 的选菜算法：recommend_recipes 按现有食材推荐，search_recipes 条件检索，check_incompatible 食材相克，get_recipe 菜谱详情。容器内与 nginx 共存，映射 2230 端口供 Agent 连接。

packages/mcp/tsconfig.json

@@ -0,0 +1,16 @@
+{
+  "compilerOptions": {
+    "target": "ESNext",
+    "lib": ["ESNext"],
+    "module": "ESNext",
+    "moduleResolution": "Bundler",
+    "resolveJsonModule": true,
+    "types": ["node"],
+    "strict": true,
+    "noEmit": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true
+  },
+  "include": ["src/**/*.ts"],
+  "exclude": ["node_modules", "dist"]
+}