(#15) Configure CI workflow for GitHub Actions

Configure GitHub Actions CI pipeline that runs on push and PR to
main/develop branches. Includes linting, test coverage, and build
across Node.js 20.x and 22.x. Coverage and build artifacts are
uploaded and retained for 7 days.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: adriancofie

.github/workflows/ci.yml

@@ -0,0 +1,113 @@
+name: CI
+
+on:
+  push:
+    branches: [main, develop]
+  pull_request:
+    branches: [main, develop]
+
+permissions:
+  contents: read
+  packages: read
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Install pnpm
+        uses: pnpm/action-setup@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20.x
+          cache: pnpm
+
+      - name: Authenticate GitHub Packages
+        run: echo "//npm.pkg.github.com/:_authToken=${{ secrets.GITHUB_TOKEN }}" >> .npmrc
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Run linter
+        run: pnpm run lint
+
+  test:
+    name: Test (Node ${{ matrix.node-version }})
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node-version: [20.x, 22.x]
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Install pnpm
+        uses: pnpm/action-setup@v4
+
+      - name: Setup Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node-version }}
+          cache: pnpm
+
+      - name: Authenticate GitHub Packages
+        run: echo "//npm.pkg.github.com/:_authToken=${{ secrets.GITHUB_TOKEN }}" >> .npmrc
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Run tests with coverage
+        run: pnpm run test:coverage
+
+      - name: Upload coverage report
+        if: matrix.node-version == '20.x'
+        uses: actions/upload-artifact@v4
+        with:
+          name: coverage-report
+          path: coverage/
+          retention-days: 7
+
+  build:
+    name: Build (Node ${{ matrix.node-version }})
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node-version: [20.x, 22.x]
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Install pnpm
+        uses: pnpm/action-setup@v4
+
+      - name: Setup Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node-version }}
+          cache: pnpm
+
+      - name: Authenticate GitHub Packages
+        run: echo "//npm.pkg.github.com/:_authToken=${{ secrets.GITHUB_TOKEN }}" >> .npmrc
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Build
+        run: pnpm run build
+
+      - name: Upload build artifacts
+        if: matrix.node-version == '20.x'
+        uses: actions/upload-artifact@v4
+        with:
+          name: build-output
+          path: dist/
+          retention-days: 7

package.json

@@ -115,7 +115,8 @@
 		"vitest": "^3.0.0",
 		"vitest-axe": "^0.1.0"
 	},
+	"packageManager": "pnpm@8.6.12",
 	"engines": {
-		"node": ">=18.0.0"
+		"node": ">=20.0.0"
 	}
 }