Update MIME type to text/html;profile=mcp-app

Apply MIME type change from commit 0af1532 to all examples and docs.
The profile parameter follows RFC 6838 recommendations for custom
media types, as MCP Apps is a profile of HTML rather than a new syntax.

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

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

examples/customer-segmentation-server/server.ts

@@ -116,7 +116,13 @@ const server = new McpServer({
       );
 
       return {
-        contents: [{ uri: resourceUri, mimeType: "text/html+mcp", text: html }],
+        contents: [
+          {
+            uri: resourceUri,
+            mimeType: "text/html;profile=mcp-app",
+            text: html,
+          },
+        ],
       };
     },
   );