Update dependencies and simplify build tooling

.github/workflows/firebase-hosting-merge.yml

@@ -13,6 +13,9 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version-file: '.nvmrc'
       - run: npm ci && npm run predeploy && npm run typedoc
       - uses: FirebaseExtended/action-hosting-deploy@v0
         with:

.github/workflows/firebase-hosting-pull-request.yml

@@ -23,6 +23,9 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version-file: '.nvmrc'
       - run: npm ci && npm run predeploy && npm run typedoc
       - uses: FirebaseExtended/action-hosting-deploy@v0
         with:

.github/workflows/npm-publish.yml

@@ -20,7 +20,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4
         with:
-          node-version: 20
+          node-version-file: '.nvmrc'
       - run: npm ci
       - run: npm run build
       - run: npm test
@@ -35,7 +35,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4
         with:
-          node-version: 24
+          node-version-file: '.nvmrc'
           registry-url: https://registry.npmjs.org/
       - run: npm ci
       - run: npm run build

.github/workflows/run-tests.yml

@@ -30,7 +30,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4
         with:
-          node-version: '22.x'
+          node-version-file: '.nvmrc'
           cache: "npm"
       - run: npm ci
       - name: Install three.js 0.185.1
@@ -94,7 +94,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4
         with:
-          node-version: '22.x'
+          node-version-file: '.nvmrc'
           cache: "npm"
       - run: npm ci
       - name: Install three.js ${{ matrix.three-version }}

.nvmrc

@@ -1 +1 @@
-v22.12.0
+v24.21.0

CONTRIBUTING.md

@@ -14,6 +14,9 @@ Other things that are always helpful:
 
 ## Development setup
 
+Use Node 24 (the exact version is pinned in `.nvmrc` and shared by CI, demo
+builds, and publishing). With nvm installed, run `nvm install && nvm use` first.
+
 Run the dev setup:
 
 ```sh
@@ -108,7 +111,7 @@ Run the full check suite:
 
 To auto-fix simple issues: `npm run lint:fix` or `npm run prettier:fix`.
 
-CI runs `build`, `test:coverage`, `typeCheck` and `lint` on Ubuntu with Node 22.
+CI runs `build`, `test:coverage`, `typeCheck` and `lint` on Ubuntu with Node 24 from `.nvmrc`.
 Note that CI uses `npm run test:coverage`, not `npm run test`: **every file under
 `src/` must be at 100% statement/branch/function/line coverage** (see
 `vitest.config.mts`), so run it locally before pushing.