Use content instead of structuredContent in examples

Not all MCP clients support structuredContent in MCP tool results, so
examples now return data as JSON in content and parse it client-side.

Pattern used:
- Server: content: [{ type: "text", text: JSON.stringify(data) }]
- Client: JSON.parse(result.content!.filter(...).map(...).join(""))

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

examples/basic-server-react/src/mcp-app.tsx

@@ -20,8 +20,12 @@ const log = {
 
 
 function extractTime(callToolResult: CallToolResult): string {
-  const { time } = (callToolResult.structuredContent as { time?: string }) ?? {};
-  return time ?? "[ERROR]";
+  const text = callToolResult.content!
+    .filter((c): c is { type: "text"; text: string } => c.type === "text")
+    .map((c) => c.text)
+    .join("");
+  const { time } = JSON.parse(text) as { time: string };
+  return time;
 }