chore: add GitHub Actions CI and release workflows

.github/workflows/ci.yml

@@ -0,0 +1,101 @@
+name: CI
+
+on:
+  pull_request:
+    branches:
+      - master
+  push:
+    branches:
+      - master
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ci-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  test:
+    name: Test
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
+        with:
+          persist-credentials: false
+
+      - name: Set up Node.js
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
+        with:
+          node-version: 24
+          package-manager-cache: false
+
+      - name: Set up pnpm
+        uses: pnpm/action-setup@0ebf47130e4866e96fce0953f49152a61190b271 # v6
+        with:
+          version: 11.5.1
+          run_install: false
+          cache: false
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Run tests
+        run: pnpm run test
+
+  typecheck:
+    name: Typecheck
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
+        with:
+          persist-credentials: false
+
+      - name: Set up Node.js
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
+        with:
+          node-version: 24
+          package-manager-cache: false
+
+      - name: Set up pnpm
+        uses: pnpm/action-setup@0ebf47130e4866e96fce0953f49152a61190b271 # v6
+        with:
+          version: 11.5.1
+          run_install: false
+          cache: false
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Run TypeScript checks
+        run: pnpm exec tsc -p tsconfig.json --noEmit
+
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
+        with:
+          persist-credentials: false
+
+      - name: Set up Node.js
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
+        with:
+          node-version: 24
+          package-manager-cache: false
+
+      - name: Set up pnpm
+        uses: pnpm/action-setup@0ebf47130e4866e96fce0953f49152a61190b271 # v6
+        with:
+          version: 11.5.1
+          run_install: false
+          cache: false
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Run lint
+        run: pnpm run lint

.github/workflows/release.yml

@@ -0,0 +1,87 @@
+name: Release
+
+on:
+  push:
+    tags:
+      - v*
+
+permissions:
+  contents: read
+
+concurrency:
+  group: release-${{ github.ref }}
+  cancel-in-progress: false
+
+jobs:
+  publish:
+    name: Build and publish
+    runs-on: ubuntu-latest
+    environment: npm-publish
+    permissions:
+      contents: read
+      id-token: write
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
+        with:
+          fetch-depth: 0
+          persist-credentials: false
+
+      - name: Verify release tag
+        shell: bash
+        run: |
+          set -euo pipefail
+
+          version="$(node -p "require('./package.json').version")"
+          tag="${GITHUB_REF_NAME}"
+
+          if [[ "${tag}" != "v${version}" ]]; then
+            echo "Release tag ${tag} does not match package version ${version}."
+            exit 1
+          fi
+
+          tag_commit="$(git rev-list -n 1 "${tag}")"
+          git fetch --no-tags origin master
+
+          if ! git merge-base --is-ancestor "${tag_commit}" origin/master; then
+            echo "Release tag ${tag} does not point to a commit reachable from origin/master."
+            exit 1
+          fi
+
+      - name: Set up Node.js
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
+        with:
+          node-version: 24
+          registry-url: https://registry.npmjs.org
+          package-manager-cache: false
+
+      - name: Set up pnpm
+        uses: pnpm/action-setup@0ebf47130e4866e96fce0953f49152a61190b271 # v6
+        with:
+          version: 11.5.1
+          run_install: false
+          cache: false
+
+      - name: Install dependencies without cache
+        run: pnpm install --frozen-lockfile
+
+      - name: Run tests
+        run: pnpm run test
+
+      - name: Run TypeScript checks
+        run: pnpm exec tsc -p tsconfig.json --noEmit
+
+      - name: Run lint
+        run: pnpm run lint
+
+      - name: Clean build output
+        run: pnpm run clean
+
+      - name: Build package
+        run: pnpm run build
+
+      - name: Inspect package contents
+        run: npm pack --dry-run
+
+      - name: Publish to npm
+        run: npm publish --access public