Added workflow to run e2e tests on merge

.github/workflows/e2e.yml

@@ -0,0 +1,42 @@
+name: E2E tests
+
+on:
+  push:
+    branches: [master]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  e2e:
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    steps:
+      - name: Check out source
+        uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4
+        with:
+          persist-credentials: false
+
+      - name: Set up Node.js
+        uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+        with:
+          node-version: 22
+          cache: npm
+
+      - name: Install dependencies
+        run: npm ci --legacy-peer-deps
+
+      - name: Run e2e tests
+        env:
+          JEST_JUNIT_OUTPUT_DIR: ${{ runner.temp }}/e2e-results
+        run: npm run e2e -- --ci --runInBand
+
+      - name: Upload test report
+        if: always()
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        with:
+          name: e2e-results
+          path: ${{ runner.temp }}/e2e-results/junit.xml
+          if-no-files-found: warn
+          retention-days: 14

.gitignore

@@ -11,8 +11,9 @@ node_modules
 /test-results.xml
 
 .vscode/
+.idea
 coverage/
 
 junit.xml
 .claude
-.cursor
+.cursor

CONTRIBUTING.md

@@ -17,3 +17,17 @@ All third-party contributions to this project must be accompanied by a signed co
 All submissions should come in the form of pull requests and need to be reviewed by project committers. Read [GitHub's pull request documentation](https://help.github.com/articles/about-pull-requests/) for more information on sending pull requests.
 
 Lastly, please follow the [pull request template](PULL_REQUEST_TEMPLATE.md) when submitting a pull request!
+
+## End-to-end tests
+
+The `E2E tests` GitHub Actions workflow runs after each push to `master`, including
+merged pull requests, and can also be started manually using `workflow_dispatch`.
+It uses Node.js 22 on Ubuntu and installs dependencies from the committed lockfile.
+This is a post-merge regression check, not a merge or publishing gate.
+
+To run the same suite locally:
+
+```sh
+npm ci --legacy-peer-deps
+npm run e2e -- --ci --runInBand
+```