fix: bump CI Node.js from 20.18.0 to 22.x to fix npm ci crash

npm ci was crashing with "Exit handler never called!" because the
package-lock.json was generated with npm 11.x (Node 22) but CI ran
npm 10.8.2 (Node 20.18.0). This left node_modules empty, causing
all subsequent build steps to fail. Node 22 LTS also satisfies the
^20.19.0 engine requirements of eslint devDependencies.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: modesty

.github/workflows/ci.yml

@@ -23,10 +23,10 @@ jobs:
         with:
           bun-version: 1.2.19
 
-      - name: Setup Node.js 20.18.0
+      - name: Setup Node.js 22.x
         uses: actions/setup-node@v4
         with:
-          node-version: 20.18.0
+          node-version: 22
 
       - name: Install dependencies
         run: npm ci