ci: add e2e tests to PR checks

Add a PR E2E workflow that runs the Playwright onboarding test on
every PR targeting master. Generates a minimal config file and lets
Playwright manage the server lifecycle. Runs in skip_llm mode so
no secrets are required.

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

.github/workflows/pr-e2e.yml

@@ -0,0 +1,70 @@
+name: PR E2E
+
+on:
+  pull_request:
+    branches:
+      - master
+
+concurrency:
+  group: pr-e2e-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
+jobs:
+  e2e:
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v4
+        with:
+          version: 9.15.4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: pnpm
+
+      - name: Install dependencies
+        run: pnpm install --no-frozen-lockfile
+
+      - name: Build
+        run: pnpm build
+
+      - name: Install Playwright
+        run: npx playwright install --with-deps chromium
+
+      - name: Generate Paperclip config
+        run: |
+          mkdir -p ~/.paperclip/instances/default
+          cat > ~/.paperclip/instances/default/config.json << 'CONF'
+          {
+            "$meta": { "version": 1, "updatedAt": "2026-01-01T00:00:00.000Z", "source": "onboard" },
+            "database": { "mode": "embedded-postgres" },
+            "logging": { "mode": "file" },
+            "server": { "deploymentMode": "local_trusted", "host": "127.0.0.1", "port": 3100 },
+            "auth": { "baseUrlMode": "auto" },
+            "storage": { "provider": "local_disk" },
+            "secrets": { "provider": "local_encrypted", "strictMode": false }
+          }
+          CONF
+
+      - name: Run e2e tests
+        env:
+          PAPERCLIP_E2E_SKIP_LLM: "true"
+          CI: ""
+        run: pnpm run test:e2e
+
+      - name: Upload Playwright report
+        uses: actions/upload-artifact@v4
+        if: always()
+        with:
+          name: playwright-report
+          path: |
+            tests/e2e/playwright-report/
+            tests/e2e/test-results/
+          retention-days: 14