chore: pin Node.js runtime and make root TS strict mode explicit (#3501)

Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com>
Co-authored-by: Claude <noreply@anthropic.com>

.github/workflows/autofix.yml

@@ -32,7 +32,7 @@ jobs:
       - name: Setup Node
         uses: actions/setup-node@v6
         with:
-          node-version: "lts/*"
+          node-version-file: ".nvmrc"
           cache: "pnpm"
 
       - name: Install Dependencies

.github/workflows/e2e.yml

@@ -50,7 +50,7 @@ jobs:
       - name: Setup Node
         uses: actions/setup-node@v6
         with:
-          node-version: "24"
+          node-version-file: ".nvmrc"
           cache: "pnpm"
 
       - name: Install Dependencies