ci: add release action to publish to NPM

.github/changeset-version.js

@@ -0,0 +1,11 @@
+// ORIGINALLY FROM CLOUDFLARE WRANGLER:
+// https://github.com/cloudflare/wrangler2/blob/main/.github/changeset-version.js
+import { exec } from 'child_process';
+
+// This script is used by the `release.yml` workflow to update the version of the packages being released.
+// The standard step is only to run `changeset version` but this does not update the lockfile.
+// So we also run `pnpm install`, which does this update.
+// This is a workaround until this is handled automatically by `changeset version`.
+// See https://github.com/changesets/changesets/issues/421.
+exec('npx changeset version');
+exec('npm install');

.github/workflows/release.yml

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+name: Release
+
+on:
+  push:
+    branches:
+      - main
+
+concurrency: ${{ github.workflow }}-${{ github.ref }}
+
+env:
+  PNPM_VERSION: 9.12.2
+
+jobs:
+  release:
+    name: release
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Setup & Install Node.js
+        uses: actions/setup-node@v3
+        with:
+          node-version-file: .node-version
+
+      - name: Install pnpm
+        uses: pnpm/action-setup@v4
+        id: pnpm-install
+        with:
+          version: ${{ env.PNPM_VERSION }}
+          run_install: false
+
+      - name: Get pnpm store directory
+        id: pnpm-cache
+        run: |
+          echo "pnpm_cache_dir=$(pnpm store path)" >> $GITHUB_OUTPUT
+
+      - name: Setup pnpm cache
+        uses: actions/cache@v4
+        with:
+          path: ${{ steps.pnpm-cache.outputs.pnpm_cache_dir }}
+          key: ${{ runner.os }}-pnpm-store-${{ hashFiles('**/pnpm-lock.yaml') }}
+          restore-keys: |
+            ${{ runner.os }}-pnpm-store-
+
+      - name: Install dependencies
+        run: pnpm install --ignore-scripts --frozen-lockfile
+
+      - name: Build the project
+        run: pnpm build
+
+      - name: Create Version PR or Publish to NPM
+        id: changesets
+        uses: changesets/[email protected]
+        with:
+          commit: 'chore(release): version packages'
+          title: 'chore(release): version packages'
+          version: node .github/changeset-version.js
+          publish: npx changeset publish
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          NPM_TOKEN: ${{ secrets.NPM_ACCESS_TOKEN }}
+          NODE_ENV: 'production'