fix(examples): use server.registerTool for non-UI tool + fix missing imports (#173)

* fix(threejs-server): use server.registerTool for non-UI tool

The learn_threejs tool doesn't have a UI component - it only returns
documentation text. Using registerAppTool without _meta causes a
runtime error when the function tries to access config._meta.ui.

Fixes crash: "Cannot read property 'ui' of undefined"

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

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

* fix(examples): add missing registerAppTool and registerAppResource imports

All example servers were using registerAppTool and registerAppResource
but not importing them from @modelcontextprotocol/ext-apps/server,
causing "ReferenceError: registerAppTool is not defined" at runtime.

Affected servers:
- budget-allocator-server
- cohort-heatmap-server
- customer-segmentation-server
- scenario-modeler-server
- system-monitor-server
- threejs-server
- wiki-explorer-server

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

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

---------

Co-authored-by: Claude <noreply@anthropic.com>

examples/budget-allocator-server/server.ts

@@ -16,6 +16,8 @@ import { z } from "zod";
 import {
   RESOURCE_MIME_TYPE,
   RESOURCE_URI_META_KEY,
+  registerAppResource,
+  registerAppTool,
 } from "@modelcontextprotocol/ext-apps/server";
 import { startServer } from "../shared/server-utils.js";
 

examples/cohort-heatmap-server/server.ts

@@ -7,6 +7,8 @@ import { z } from "zod";
 import {
   RESOURCE_MIME_TYPE,
   RESOURCE_URI_META_KEY,
+  registerAppResource,
+  registerAppTool,
 } from "@modelcontextprotocol/ext-apps/server";
 import { startServer } from "../shared/server-utils.js";
 

examples/customer-segmentation-server/server.ts

@@ -10,6 +10,8 @@ import { z } from "zod";
 import {
   RESOURCE_MIME_TYPE,
   RESOURCE_URI_META_KEY,
+  registerAppResource,
+  registerAppTool,
 } from "@modelcontextprotocol/ext-apps/server";
 import { startServer } from "../shared/server-utils.js";
 import {

examples/scenario-modeler-server/server.ts

@@ -10,6 +10,8 @@ import { z } from "zod";
 import {
   RESOURCE_MIME_TYPE,
   RESOURCE_URI_META_KEY,
+  registerAppResource,
+  registerAppTool,
 } from "@modelcontextprotocol/ext-apps/server";
 import { startServer } from "../shared/server-utils.js";
 

examples/system-monitor-server/server.ts

@@ -12,6 +12,8 @@ import { z } from "zod";
 import {
   RESOURCE_MIME_TYPE,
   RESOURCE_URI_META_KEY,
+  registerAppResource,
+  registerAppTool,
 } from "@modelcontextprotocol/ext-apps/server";
 import { startServer } from "../shared/server-utils.js";
 

examples/threejs-server/server.ts

@@ -12,6 +12,8 @@ import { z } from "zod";
 import {
   RESOURCE_MIME_TYPE,
   RESOURCE_URI_META_KEY,
+  registerAppResource,
+  registerAppTool,
 } from "@modelcontextprotocol/ext-apps/server";
 import { startServer } from "../shared/server-utils.js";
 
@@ -178,9 +180,8 @@ function createServer(): McpServer {
     },
   );
 
-  // Tool 2: learn_threejs
-  registerAppTool(
-    server,
+  // Tool 2: learn_threejs (not a UI tool, just returns documentation)
+  server.registerTool(
     "learn_threejs",
     {
       title: "Learn Three.js",

examples/wiki-explorer-server/server.ts

@@ -11,6 +11,8 @@ import { z } from "zod";
 import {
   RESOURCE_MIME_TYPE,
   RESOURCE_URI_META_KEY,
+  registerAppResource,
+  registerAppTool,
 } from "@modelcontextprotocol/ext-apps/server";
 import { startServer } from "../shared/server-utils.js";