[Agents] Add missing zod import (#25851)

Added missing `zod` import in two examples.

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Co-authored-by: Pedro Sousa <[email protected]>

Author: ashishajr

src/content/docs/agents/model-context-protocol/tools.mdx

@@ -17,6 +17,7 @@ For example, the following code from [this example MCP server](https://github.co
 ```ts title="src/index.ts"
 import { McpServer } from "@modelcontextprotocol/sdk/server/mcp";
 import { McpAgent } from "agents/mcp";
+import { z } from "zod";
 
 export class MyMCP extends McpAgent {
 	server = new McpServer({ name: "Demo", version: "1.0.0" });

src/content/docs/agents/x402.mdx

@@ -96,6 +96,7 @@ x402 supercharges your MCP servers so they can include paid tools.
 import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
 import { McpAgent } from "agents/mcp";
 import { withX402, type X402Config } from "agents/x402";
+import { z } from "zod";
 
 const X402_CONFIG: X402Config = {
 	network: "base",