docs: document smoke tests, integration tests, and add smoke-test command

.cursor/commands/smoke-test.mdc

@@ -0,0 +1,7 @@
+---
+description: Run smoke tests against the live Lambda function (requires FUNCTION_URL and WEBHOOK_SECRET in .env)
+globs:
+  - "scripts/smoke-test.js"
+  - "tests/fixtures/**/*.json"
+---
+node scripts/smoke-test.js all

CONTRIBUTING.md

@@ -32,6 +32,24 @@ pr:
 - `npm run tests:rep` run the tests with no code coverage verification and create *unit-tests-result.json*
 - `npm run lint` lint the project
 
+### Smoke testing
+
+The smoke test script sends signed webhook events to the live Lambda function and verifies HTTP responses.
+It requires `FUNCTION_URL` and `WEBHOOK_SECRET` in your `.env` file.
+
+- `node scripts/smoke-test.js ping` send a ping event
+- `node scripts/smoke-test.js all` send all event types (ping, pull_request.opened, pull_request.closed,
+  pull_request_review.submitted)
+
+Individual event types can also be run by name (e.g. `node scripts/smoke-test.js pull_request.opened`).
+The script includes retry logic to handle cold starts and propagation delays.
+
+The smoke test also runs automatically after each release via the
+[smoke-test workflow](.github/workflows/smoke-test.yml), which can be triggered manually from the GitHub Actions UI.
+
+Test payloads are stored as JSON files in [tests/fixtures/](tests/fixtures/) and are shared with the
+integration tests.
+
 ### Developing Handlers
 
 All handlers are located in [src/handlers/](https://github.com/TomerFi/auto-me-bot/tree/main/src/handlers).<br/>
@@ -110,6 +128,13 @@ module.exports.run =  async function(context, config, startedAt) {
 All handler unit tests are located in [tests/handlers/](https://github.com/TomerFi/auto-me-bot/tree/main/tests/handlers), test the *match* and *run* functions individually, you can inject fakes and stubs into these and verify their behavior.<br/>
 Take note of [pr-conventional-title test cases](https://github.com/TomerFi/auto-me-bot/blob/main/tests/handlers/pr-conventional-title.test.js) which can be used as a template for future test cases as it's quite short, simple, and has full coverage.
 
+### Integration Tests
+
+The Lambda handler entrypoint is tested in [tests/app-runner.test.js](tests/app-runner.test.js).
+These tests instantiate a real Probot instance with a generated RSA key, sign webhook payloads with HMAC-SHA256,
+and verify the handler processes events without crashing.
+Payloads are loaded from [tests/fixtures/](tests/fixtures/).
+
 ### Registering Handlers
 
 > NOTE: registering handlers requires modifying existing code, the snippets in this section are meant to help you get around the code, and to be used as boiler-plate code.
@@ -208,6 +233,7 @@ This project includes Cursor-specific helpers:
 - **run-tests-quick** - Quick test run without coverage
 - **lint-fix** - Lint and auto-fix issues
 - **serve-docs** - Serve documentation locally
+- **smoke-test** - Run smoke tests against the live Lambda function
 
 ### Agents