docs(mcp): add You.com MCP example

Add a copyable mcpServers snippet for the hosted You.com MCP server
in both docs/mcp.md (Chinese) and docs/mcp_en.md (English), so Deep
Code users can configure real-time web search, citable research,
page-content extraction, and finance research without modifying the
built-in WebSearch tool.

Two snippets are provided:

- Full toolset (you-search, you-contents, you-research, you-finance)
  via the hosted MCP bridge @youdotcom-oss/mcp, authed with YDC_API_KEY
  and scoped with YDC_ALLOWED_TOOLS.
- A keyless, no-signup variant using YDC_PROFILE=free that exposes
  only you-search (capped at 100 queries/day), for users who want to
  try web search before creating an account.

A one-line callout references PR #198, which will let users replace
the npx bridge with the native type: "http" + url + headers shape
once it merges.

Scope: doc-only. No code, settings, or test changes. Mirrors the
patch surface used by PR #268 (docs/mcp.md + docs/mcp_en.md).

Author: tyler5673

docs/mcp.md

@@ -84,6 +84,43 @@ MCP 工具在 Deep Code 中的命名格式为 `mcp__<服务名>__<工具名>`，
 }
 ```
 
+### You.com 联网搜索与研究
+
+通过 You.com MCP 服务器接入实时联网搜索、网页内容读取、可引用的多源研究和财经研究工具。`@youdotcom-oss/mcp` 是一个轻量 STDIO 桥接，把本地 MCP 请求转发到托管在 `https://api.you.com/mcp` 的远程服务器；首轮对话后，模型即可看到 `mcp__ydc__you-search` 等工具。
+
+```json
+{
+  "mcpServers": {
+    "ydc": {
+      "command": "npx",
+      "args": ["-y", "@youdotcom-oss/mcp"],
+      "env": {
+        "YDC_API_KEY": "ydc-...",
+        "YDC_ALLOWED_TOOLS": "you-search,you-contents,you-research,you-finance"
+      }
+    }
+  }
+}
+```
+
+如果想先体验联网搜索、不立刻注册账号，可以把 `YDC_PROFILE` 设为 `free`（免账号、免 Key，仅暴露 `you-search`，每天 100 次查询上限）：
+
+```json
+{
+  "mcpServers": {
+    "ydc": {
+      "command": "npx",
+      "args": ["-y", "@youdotcom-oss/mcp"],
+      "env": {
+        "YDC_PROFILE": "free"
+      }
+    }
+  }
+}
+```
+
+> API Key 在 https://you.com/platform 申请；可用工具集与计费规则见 https://you.com/docs/build-with-agents/mcp-server。
+
 ### 文件系统
 
 让 Deep Code 在指定目录中读写文件：

docs/mcp_en.md

@@ -84,6 +84,43 @@ Lets Deep Code control a browser for screenshots, page interactions, etc.:
 }
 ```
 
+### You.com Web Search & Research
+
+Connects you to You.com's real-time web search, page content extraction, citable multi-source research, and finance research via the hosted You.com MCP server at `https://api.you.com/mcp`. `@youdotcom-oss/mcp` is a minimal STDIO bridge that forwards local MCP traffic to the remote server. After the first message, the model sees tools such as `mcp__ydc__you-search`.
+
+```json
+{
+  "mcpServers": {
+    "ydc": {
+      "command": "npx",
+      "args": ["-y", "@youdotcom-oss/mcp"],
+      "env": {
+        "YDC_API_KEY": "ydc-...",
+        "YDC_ALLOWED_TOOLS": "you-search,you-contents,you-research,you-finance"
+      }
+    }
+  }
+}
+```
+
+To try web search without signing up first, set `YDC_PROFILE` to `free` (no account, no API key; exposes only `you-search`, capped at 100 queries/day):
+
+```json
+{
+  "mcpServers": {
+    "ydc": {
+      "command": "npx",
+      "args": ["-y", "@youdotcom-oss/mcp"],
+      "env": {
+        "YDC_PROFILE": "free"
+      }
+    }
+  }
+}
+```
+
+> Get an API key at https://you.com/platform; see the full tool list and pricing at https://you.com/docs/build-with-agents/mcp-server.
+
 ### File System
 
 Enables Deep Code to read and write files within a specified directory: