ci: split workflows and move pnpm lockfile ownership to GitHub Actions

.github/workflows/pr-verify.yml

@@ -0,0 +1,44 @@
+name: PR Verify
+
+on:
+  pull_request:
+    branches:
+      - master
+
+concurrency:
+  group: pr-verify-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
+jobs:
+  verify:
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v4
+        with:
+          version: 9.15.4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: pnpm
+
+      - name: Install dependencies
+        run: pnpm install --no-frozen-lockfile
+
+      - name: Typecheck
+        run: pnpm -r typecheck
+
+      - name: Run tests
+        run: pnpm test:run
+
+      - name: Build
+        run: pnpm build