Upgrade Node.js from v22 to v24 (Active LTS) (#818)

- Update .nvmrc to v24.12.0
- Update package.json engines to require Node >=24.0.0 <25 and npm >=11.0.0 <12
- Regenerate package-lock.json with npm 11 (lockfileVersion 3)
- Update Dockerfile to use node:24-bookworn base image
- Update GitHub Actions workflows to use Node 24
- Remove redundant npm global install steps (npm 11 bundled with Node 24)
- Update documentation to reflect Node 24.x requirement

This resolves Dependabot EBADENGINE errors by aligning with Dependabot's
Node v24.12.0 / npm 11.7.0 environment.

Tested locally:
- npm install completes successfully
- Build process works (npm run build)
- Linting passes (npm run ci-lint)
- Unit tests run (npm run test:run)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: Tim020

.github/workflows/build.yml

@@ -15,7 +15,7 @@ jobs:
       - name: Setup Node.js
         uses: actions/setup-node@v4
         with:
-          node-version: '22'
+          node-version: '24'
           cache: 'npm'
           cache-dependency-path: 'client/package-lock.json'
       - name: Install dependencies

.github/workflows/client-test.yml

@@ -16,9 +16,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v3
         with:
-          node-version: 22
-      - name: Install npm 10
-        run: npm install -g npm@10
+          node-version: 24
       - name: Install dependencies
         run: npm ci
       - name: Run tests

.github/workflows/nodelint.yml

@@ -12,7 +12,6 @@ jobs:
     - uses: actions/checkout@v3
     - uses: actions/setup-node@v3
       with:
-        node-version: 22
-    - run: npm install -g npm@10
+        node-version: 24
     - run: npm ci
     - run: npm run ci-lint

Dockerfile

@@ -1,6 +1,6 @@
-FROM node:22-bookworm AS node_build
+FROM node:24-bookworm AS node_build
 
-RUN npm install npm@10 -g
+# npm 11 bundled with Node 24, no separate install needed
 RUN mkdir -p /server/static
 
 COPY /client/package.json /client/package.json

README.md

@@ -14,7 +14,7 @@ A digital script project for cueing theatrical shows
 
 ### Requirements
 
-* Node v22.x (npm 10.x)
+* Node v24.x (npm 11.x)
 * Python 3.13.x
 
 ### Client