ci: use .nvmrc node version in dependency-update and deploy workflows

Point the remaining workflows at node-version-file: .nvmrc instead of a hardcoded version so all CI runs on the repo-pinned Node, and log node/npm versions for diagnostics.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: thephez

.github/workflows/dependency-update.yml

@@ -22,7 +22,12 @@ jobs:
       - name: Set up Node.js
         uses: actions/setup-node@53b83947a5a98c8d113130e565377fae1a50d02f # v6.3.0
         with:
-          node-version: '20'
+          node-version-file: .nvmrc
+
+      - name: Show Node/npm versions
+        run: |
+          node -v
+          npm -v
 
       # Step 3: Install dependencies
       - name: Install Dependencies

.github/workflows/deploy-example-apps.yml

@@ -70,10 +70,15 @@ jobs:
 
       - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
         with:
-          node-version: 24
+          node-version-file: .nvmrc
           cache: npm
           cache-dependency-path: example-apps/${{ matrix.app }}/package-lock.json
 
+      - name: Show Node/npm versions
+        run: |
+          node -v
+          npm -v
+
       - name: Install
         run: npm ci
         working-directory: example-apps/${{ matrix.app }}
@@ -113,7 +118,12 @@ jobs:
 
       - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
         with:
-          node-version: 24
+          node-version-file: .nvmrc
+
+      - name: Show Node/npm versions
+        run: |
+          node -v
+          npm -v
 
       - name: Download all built apps
         uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1