Clean up examples (#182)

* Centralize example server transport logic in shared utils

Move stdio/HTTP transport handling into `server-utils.ts` so example
servers only need to call `startServer(createServer)`. Switch HTTP
transport to stateless mode and remove legacy SSE endpoints.

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Make example servers self-contained with local server-utils

Copy `server-utils.ts` into each example's `src/` directory so examples
can be used standalone without the shared directory. Updates imports
from `"../shared/server-utils.js"` to `"./src/server-utils.js"`.

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Add `integration-server` example for E2E testing

Add dedicated `integration-server` example (duplicated from
`basic-server-react`) to preserve E2E testing capabilities while
allowing `basic-server-react` to be simplified as a minimal example.

Changes:
- Add `examples/integration-server` exercising SDK communication APIs
- Update E2E tests to use `integration-server` instead of
  `basic-server-react` and `basic-server-vanillajs`
- Use server name labels instead of indices for more robust test
  selection
- Remove `basic-react.png` and `basic-vanillajs.png` golden snapshots

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

* Simplify `basic-server-*` examples

- Clarify comments
- Return plain text from `get-time` tool instead of JSON
- Remove simulated cleanup delay from `onteardown`

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

examples/integration-server/server.ts

@@ -0,0 +1,67 @@
+import {
+  registerAppResource,
+  registerAppTool,
+  RESOURCE_MIME_TYPE,
+  RESOURCE_URI_META_KEY,
+} from "@modelcontextprotocol/ext-apps/server";
+import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import type {
+  CallToolResult,
+  ReadResourceResult,
+} from "@modelcontextprotocol/sdk/types.js";
+import fs from "node:fs/promises";
+import path from "node:path";
+import { startServer } from "./src/server-utils.js";
+
+const DIST_DIR = path.join(import.meta.dirname, "dist");
+const RESOURCE_URI = "ui://get-time/mcp-app.html";
+
+/**
+ * Creates a new MCP server instance with tools and resources registered.
+ */
+function createServer(): McpServer {
+  const server = new McpServer({
+    name: "Integration Test Server",
+    version: "1.0.0",
+  });
+
+  registerAppTool(
+    server,
+    "get-time",
+    {
+      title: "Get Time",
+      description: "Returns the current server time as an ISO 8601 string.",
+      inputSchema: {},
+      _meta: { [RESOURCE_URI_META_KEY]: RESOURCE_URI },
+    },
+    async (): Promise<CallToolResult> => {
+      const time = new Date().toISOString();
+      return {
+        content: [{ type: "text", text: JSON.stringify({ time }) }],
+      };
+    },
+  );
+
+  registerAppResource(
+    server,
+    RESOURCE_URI,
+    RESOURCE_URI,
+    { mimeType: RESOURCE_MIME_TYPE },
+    async (): Promise<ReadResourceResult> => {
+      const html = await fs.readFile(
+        path.join(DIST_DIR, "mcp-app.html"),
+        "utf-8",
+      );
+
+      return {
+        contents: [
+          { uri: RESOURCE_URI, mimeType: RESOURCE_MIME_TYPE, text: html },
+        ],
+      };
+    },
+  );
+
+  return server;
+}
+
+startServer(createServer);