ci: add pkg.pr.new workflow for continuous package previews (#46)

Publishes preview versions of the package on every push and PR,
allowing reviewers to install and test exact commit builds.

.github/workflows/pkg-pr-new.yml

@@ -0,0 +1,29 @@
+name: Publish Any Commit
+
+on:
+  push:
+    branches: [main, dev]
+  pull_request:
+    branches: [main, dev]
+
+permissions: {}
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Build
+        run: npm run build
+
+      - name: Publish to pkg.pr.new
+        run: npx pkg-pr-new publish