chore: raise the minimum supported Node.js runtime to 20

Node.js 18 is EOL and the toolchain init installs no longer supports it:
current Playwright releases and the skills CLI both require Node.js 20+.
Bump engines for screenci and create-screenci, run the CI smoke matrix on
Node.js 20, and update the setup docs.

.github/workflows/ci.yml

@@ -63,17 +63,17 @@ jobs:
       - name: Setup pnpm
         uses: pnpm/action-setup@v6
         with:
-          # pnpm 11 uses syntax that Node.js 18 cannot parse. Keep smoke tests on
-          # the minimum supported pnpm release so the Node.js 18 baseline remains
-          # covered end to end.
+          # Keep smoke tests on the minimum supported pnpm release so the
+          # Node.js 20 baseline remains covered end to end.
           version: 10.26.0
 
       - name: Setup Node.js
         uses: actions/setup-node@v6
         with:
-          # Smoke tests stay on the minimum supported runtime so CLI init/test flows
-          # are continuously verified against the Node.js 18 baseline.
-          node-version: 18
+          # Smoke tests stay on the minimum supported runtime so CLI init/test
+          # flows are continuously verified against the Node.js 20 baseline
+          # (Node.js 18 is EOL and current Playwright releases require 20+).
+          node-version: 20
           cache: pnpm
           cache-dependency-path: pnpm-lock.yaml
 

create-screenci/package.json

@@ -9,7 +9,7 @@
   "license": "MIT",
   "author": "ScreenCI Ltd",
   "engines": {
-    "node": ">=18"
+    "node": ">=20"
   },
   "repository": {
     "type": "git",

docs/manual-setup.mdx

@@ -48,7 +48,7 @@ yarn create screenci
   </TabItem>
 </Tabs>
 
-If that does not work, install [Node.js 18 or newer](https://nodejs.org/en/download),
+If that does not work, install [Node.js 20 or newer](https://nodejs.org/en/download),
 which comes with npm.
 
 No account or setup token is needed: the scaffolded project records immediately

package.json

@@ -8,7 +8,7 @@
   "license": "MIT",
   "author": "ScreenCI Ltd",
   "engines": {
-    "node": ">=18"
+    "node": ">=20"
   },
   "repository": {
     "type": "git",