[Demo] Modernize TypeScript demos to NodeNext + ES2022 (#1534)

## 1. ESM migration of `example/` (44 files)
Converted every CommonJS example to native ESM (`.cjs` → `.mjs`):
- Dropped `'use strict'`, replaced `require('…/index.js').default` with `import rclnodejs from '…/index.js'`.
- Unwrapped `main()` / `.then().catch()` into top-level `await` + `try/catch`.
- Preserved original copyright headers.
- Updated all 10 example READMEs (`.cjs` → `.mjs`, plus the "import rclnodejs from 'rclnodejs'" note).

## 2. ESM migration of demos (3 files)
- `demo/rosocket/server.cjs` → `server.mjs`
- `demo/web/javascript/runtime.cjs` → `runtime.mjs`
- `demo/web/javascript/static.cjs` → `static.mjs` (adds `__dirname` shim via `fileURLToPath`)
- Directory imports made explicit (`../../rosocket/index.js`, `../../../lib/runtime/index.js`).
- Updated `demo/rosocket/README.md`, `demo/web/javascript/README.md`, and `demo/web/typescript/server.ts` comments.

## 3. demo/typescript modernization (no .cjs→.mjs)
- `actions/`, `services/`, `topics/` `tsconfig.json`: `module`/`moduleResolution` → `NodeNext`, `target`/`lib` → ES2022, removed stale `./types` typeRoots.
- Updated `README.md` + per-folder READMEs (ES2022 wording, removed false "local type definitions" claims).

## 4. ESM fix for benchmarks (4 files)
`benchmark/rclnodejs/**/*.js` used bare `require()` under the root `"type": "module"` and threw `ReferenceError: require is not defined`. Converted to ESM (`import { program } from 'commander'`, `import rclnodejs from '../../../index.js'`). Verified against ROS 2 Jazzy: topic + service pairs run with no exceptions.

## 5. CommonJS island fix for jsdoc tooling (1 file)
Added `tools/jsdoc/package.json` = `{"type":"commonjs"}` so `build-index.js`, `regenerate-published-docs.js`, and the jsdoc template `publish.js` (which must keep that exact name and be CJS) load correctly. Without it, `npm run docs` aborts with "Unable to load template: require is not defined". Verified: `npm run docs` now exits 0.

## 6. Root README ESM conversion (`README.md`, 13/13 lines)
- Top publisher snippet: `require('rclnodejs')` + `.init().then()` → `import rclnodejs from 'rclnodejs'` + top-level `await`.
- Observable snippet: `require('rxjs')` → `import { throttleTime, map } from 'rxjs'`.
- Message-generation snippet: `require('rclnodejs')` → `import rclnodejs from 'rclnodejs'`.
- Quick Start: stale `publisher-example.cjs` → `publisher-example.mjs`.
- TypeScript `tsconfig` snippet → `module: NodeNext`, `moduleResolution: NodeNext`, `target: es2022`.

Fix: #1358

Author: minggangw

README.md

@@ -16,13 +16,13 @@
 **Key features:** Topics, Services, Actions, Parameters, Lifecycle Nodes, TypeScript support, RxJS Observables, Electron integration, ROS 2 in the browser (typed Web SDK + thin WebSocket gateway — `rclnodejs/web`, `rosocket`), and prebuilt binaries for Linux x64/arm64.
 
 ```javascript
-const rclnodejs = require('rclnodejs');
-rclnodejs.init().then(() => {
-  const node = new rclnodejs.Node('publisher_example_node');
-  const publisher = node.createPublisher('std_msgs/msg/String', 'topic');
-  publisher.publish(`Hello ROS 2 from rclnodejs`);
-  node.spin();
-});
+import rclnodejs from 'rclnodejs';
+
+await rclnodejs.init();
+const node = new rclnodejs.Node('publisher_example_node');
+const publisher = node.createPublisher('std_msgs/msg/String', 'topic');
+publisher.publish(`Hello ROS 2 from rclnodejs`);
+node.spin();
 ```
 
 This example assumes your ROS 2 environment is already sourced.
@@ -105,7 +105,7 @@ npm install
 2. Run a publisher example from this checkout.
 
 ```bash
-node example/topics/publisher/publisher-example.cjs
+node example/topics/publisher/publisher-example.mjs
 ```
 
 More runnable examples in [example/](https://github.com/RobotWebTools/rclnodejs/tree/develop/example) and step-by-step guides in [tutorials/](./tutorials/).
@@ -146,7 +146,7 @@ how much glue you want to write.
 rclnodejs supports [RxJS](https://rxjs.dev/) Observable subscriptions for reactive programming with ROS 2 messages. Use operators like `throttleTime()`, `debounceTime()`, `map()`, and `combineLatest()` to build declarative message processing pipelines.
 
 ```javascript
-const { throttleTime, map } = require('rxjs');
+import { throttleTime, map } from 'rxjs';
 
 const obsSub = node.createObservableSubscription(
   'sensor_msgs/msg/LaserScan',
@@ -173,7 +173,7 @@ rclnodejs auto-generates JavaScript bindings and TypeScript declarations for eve
 Use the generated types directly:
 
 ```javascript
-const rclnodejs = require('rclnodejs');
+import rclnodejs from 'rclnodejs';
 let stringMsgObject = rclnodejs.createMessageObject('std_msgs/msg/String');
 stringMsgObject.data = 'hello world';
 ```
@@ -199,9 +199,9 @@ TypeScript declaration files are included in the package and exposed through the
 ```jsonc
 {
   "compilerOptions": {
-    "module": "commonjs",
-    "moduleResolution": "node",
-    "target": "es2020",
+    "module": "NodeNext",
+    "moduleResolution": "NodeNext",
+    "target": "es2022",
   },
 }
 ```

benchmark/rclnodejs/service/client-stress-test.js

@@ -12,11 +12,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-'use strict';
-
 /* eslint-disable camelcase */
-const { program } = require('commander');
-const rclnodejs = require('../../../index.js');
+import { program } from 'commander';
+import rclnodejs from '../../../index.js';
 
 program
   .option('-r, --run <n>', 'How many times to run', '1')

benchmark/rclnodejs/service/service-stress-test.js

@@ -12,11 +12,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-'use strict';
-
 /* eslint-disable camelcase */
-const { program } = require('commander');
-const rclnodejs = require('../../../index.js');
+import { program } from 'commander';
+import rclnodejs from '../../../index.js';
 
 program
   .option('-s, --size <size_kb>', 'The block size in KB', '1')

benchmark/rclnodejs/topic/publisher-stress-test.js

@@ -12,11 +12,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-'use strict';
-
 /* eslint-disable camelcase */
-const { program } = require('commander');
-const rclnodejs = require('../../../index.js');
+import { program } from 'commander';
+import rclnodejs from '../../../index.js';
 
 program
   .option('-s, --size <size_kb>', 'The block size', '1')

benchmark/rclnodejs/topic/subscription-stress-test.js

@@ -12,9 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-'use strict';
-
-const rclnodejs = require('../../../index.js');
+import rclnodejs from '../../../index.js';
 
 async function main() {
   try {

demo/rosocket/README.md

@@ -11,12 +11,12 @@ library required.
 - Subscribe to and publish on `/chatter` (`std_msgs/msg/String`).
 - Call `/add_two_ints` (`example_interfaces/srv/AddTwoInts`) — the
   service implementation lives in
-  [`example/services/service/service-example.cjs`](../../example/services/service/service-example.cjs)
+  [`example/services/service/service-example.mjs`](../../example/services/service/service-example.mjs)
   and is launched in a second terminal.
 
 ## Layout
 
-- `server.cjs` — `rclnodejs` node + `startRosocket` bridge only.
+- `server.mjs` — `rclnodejs` node + `startRosocket` bridge only.
 - `index.html` — single-file browser client using only built-in
   `WebSocket` and `JSON`.
 
@@ -27,12 +27,12 @@ library required.
 source /opt/ros/$ROS_DISTRO/setup.bash
 
 # 2. Terminal A — start the WebSocket gateway
-node demo/rosocket/server.cjs
+node demo/rosocket/server.mjs
 # [rosocket-demo] listening on ws://localhost:9000 (bind=0.0.0.0)
 
 # 3. Terminal B — start the AddTwoInts service so the browser has
 #    something to call
-node example/services/service/service-example.cjs
+node example/services/service/service-example.mjs
 ```
 
 The server binds to `0.0.0.0:9000` so it is reachable from any host

demo/rosocket/server.cjs

@@ -0,0 +1,69 @@
+// Copyright (c) 2026 RobotWebTools Contributors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+
+// rosocket demo server.
+//
+// Bridges two ROS 2 endpoints to plain WebSocket URLs so a browser can
+// drive them with built-in `WebSocket` + `JSON`, no client library:
+//
+//   ws://<host>:9000/topic/chatter        std_msgs/msg/String
+//   ws://<host>:9000/service/add_two_ints example_interfaces/srv/AddTwoInts
+//
+// Run inside WSL (where ROS 2 is sourced):
+//   node demo/rosocket/server.mjs
+//
+// To exercise the service, start the existing AddTwoInts example in a
+// second terminal (it implements `/add_two_ints`):
+//   node example/services/service/service-example.mjs
+//
+// Then open demo/rosocket/index.html on the Windows host browser. WSL2
+// forwards localhost so `ws://localhost:9000` works as-is. See README.md
+// for fallback instructions.
+
+import rclnodejs from '../../index.js';
+import { startRosocket } from '../../rosocket/index.js';
+
+const PORT = Number(process.env.PORT) || 9000;
+const HOST = process.env.HOST || '0.0.0.0';
+
+await rclnodejs.init();
+const node = rclnodejs.createNode('rosocket_demo_node');
+rclnodejs.spin(node);
+
+const bridge = await startRosocket({
+  node,
+  port: PORT,
+  host: HOST,
+  topicTypes: {
+    '/chatter': 'std_msgs/msg/String',
+  },
+  serviceTypes: {
+    '/add_two_ints': 'example_interfaces/srv/AddTwoInts',
+  },
+});
+
+const displayHost = HOST === '0.0.0.0' || HOST === '::' ? 'localhost' : HOST;
+const baseUrl = `ws://${displayHost}:${bridge.port}`;
+console.log(
+  `[rosocket-demo] listening on ${baseUrl} (bind=${HOST}:${bridge.port})`
+);
+console.log('[rosocket-demo] endpoints:');
+console.log(`  ${baseUrl}/topic/chatter`);
+console.log(`  ${baseUrl}/service/add_two_ints`);
+console.log('Open demo/rosocket/index.html in the host browser to try it.');
+
+const shutdown = () => {
+  bridge.close().finally(() => {
+    try {
+      rclnodejs.shutdown();
+    } catch (_) {}
+    process.exit(0);
+  });
+};
+process.on('SIGINT', shutdown);
+process.on('SIGTERM', shutdown);

demo/rosocket/server.mjs

@@ -42,7 +42,7 @@ Asynchronous actions with progress feedback and cancellation
 
 ### Modern Development
 
-- **ES2020+ syntax** with async/await patterns
+- **ES2022+ syntax** with async/await patterns
 - **Modular architecture** with clean separation of concerns
 - **Error boundaries** with comprehensive exception handling
 - **Graceful shutdown** handling for SIGINT/SIGTERM

demo/typescript/README.md

@@ -36,8 +36,6 @@ demo/typescript/actions/
 ├── src/
 │   ├── client.ts          # Action client implementation
 │   └── server.ts          # Action server implementation
-├── types/
-│   └── rclnodejs.d.ts     # Type definitions
 ├── package.json           # Project configuration
 ├── tsconfig.json          # TypeScript configuration
 ├── .gitignore            # Git ignore rules