chore(deps): drop Node 20 — EOL 2026-04-30

Node 20.x reached end-of-life on 2026-04-30 and the test runner on Windows
exhibits different exit semantics than 22+ (the routes.test.js after()
process.exit shim cancels the synthetic file wrapper on 20 even though
every assertion passes), so keeping it in the matrix would force us to
maintain a divergent code path for an unsupported runtime.

* package.json engines: node >=22.0.0
* CI matrix: drop Node 20, keep 22 + 24
* Docs: getting-started.md, troubleshooting.md, running-in-background.md
  bumped to "Node.js 22 or higher"
* Copilot instructions cross-platform note bumped

No code changes. The routes.test.js Windows worker-exit shim added in the
prior commit stays — it's still needed for clean Windows runs on 22 and 24.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: dorlugasigal

.github/copilot-instructions.md

@@ -107,7 +107,7 @@ TermBeam is a Node.js CLI tool that exposes a local PTY (pseudo-terminal) over H
 - **Minimal dependencies** — prefer built-in Node.js APIs over npm packages
 - **One responsibility per file** — modules organized in `src/server/`, `src/cli/`, `src/tunnel/`, `src/utils/`, each owning a single concern
 - **Prettier formatting** — single quotes, trailing commas, 100 char width, semicolons (`.prettierrc`)
-- **Cross-platform support** — must work on Windows, macOS, and Linux; CI tests on Ubuntu + Windows with Node 20, 22, 24
+- **Cross-platform support** — must work on Windows, macOS, and Linux; CI tests on Ubuntu + Windows with Node 22 and 24 (Node 20 was dropped after its EOL on 2026-04-30; bump `package.json` engines + this line in lockstep)
 - **PTY session cleanup** — `pty.kill()` is async; the `onExit` callback removes the session from the Map
 - **Coverage exclusion** — `src/tunnel/` directory is excluded from coverage (requires external DevTunnel CLI)
 - **Build artifact** — `public/` is a gitignored build artifact; run `npm run build:frontend` to regenerate from `src/frontend/`

.github/workflows/ci.yml

@@ -21,7 +21,8 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, windows-latest]
-        node-version: [20, 22, 24]
+        # Node 20 dropped after EOL (2026-04-30). See package.json engines.
+        node-version: [22, 24]
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
       - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6

package.json

@@ -48,7 +48,7 @@
     "url": "https://github.com/dorlugasigal/TermBeam/issues"
   },
   "engines": {
-    "node": ">=20.0.0"
+    "node": ">=22.0.0"
   },
   "files": [
     "bin/",

packages/site/src/content/docs/getting-started.md

@@ -5,7 +5,7 @@ description: Install TermBeam and connect to your terminal from any device in un
 
 ## Prerequisites
 
-- **Node.js** 20 or higher
+- **Node.js** 22 or higher
 - A terminal (macOS, Linux, or Windows)
 
 ## Installation

packages/site/src/content/docs/running-in-background.md

@@ -343,7 +343,7 @@ If you use `--tunnel` with a background service, pass `--persisted-tunnel` so th
 
 <!-- prettier-ignore -->
 :::tip[Node.js Requirement]
-TermBeam requires Node.js 20 or higher. Verify with `node --version` before setting up a background service.
+TermBeam requires Node.js 22 or higher (Node 20 was dropped after its EOL on 2026-04-30). Verify with `node --version` before setting up a background service.
 :::
 
 <!-- prettier-ignore -->

packages/site/src/content/docs/troubleshooting.md

@@ -151,7 +151,7 @@ curl -H "Authorization: Bearer YOUR_PASSWORD" http://localhost:3456/api/sessions
 - **Alpine (Docker):** `apk add build-base python3`
 - **Windows (Admin PowerShell):** `npm install --global windows-build-tools`
 
-Ensure your Node.js version is 20 or higher — older versions are not supported.
+Ensure your Node.js version is 22 or higher — older versions (including Node 20, EOL 2026-04-30) are not supported.
 
 ### "Port already in use"