docs: restore educational comments in basic-server examples

Addresses PR review feedback to preserve explanatory comments
that help developers understand the MCP App registration pattern.

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

Co-Authored-By: Claude <[email protected]>

Author: ochafik

examples/basic-server-react/server.ts

@@ -17,8 +17,12 @@ export function createServer(): McpServer {
     version: "1.0.0",
   });
 
+  // Two-part registration: tool + resource, tied together by the resource URI.
   const resourceUri = "ui://get-time/mcp-app.html";
 
+  // Register a tool with UI metadata. When the host calls this tool, it reads
+  // `_meta[RESOURCE_URI_META_KEY]` to know which resource to fetch and render
+  // as an interactive UI.
   registerAppTool(server,
     "get-time",
     {
@@ -32,6 +36,7 @@ export function createServer(): McpServer {
     },
   );
 
+  // Register the resource, which returns the bundled HTML/JavaScript for the UI.
   registerAppResource(server,
     resourceUri,
     resourceUri,

examples/basic-server-vanillajs/server.ts

@@ -38,6 +38,7 @@ export function createServer(): McpServer {
     },
   );
 
+  // Register the resource, which returns the bundled HTML/JavaScript for the UI.
   registerAppResource(server,
     RESOURCE_URI,
     RESOURCE_URI,