Add shared Maestro checkout smoke flow

e2e/README.md

@@ -1,12 +1,45 @@
 # Checkout Kit End-to-End Tests
 
-This directory is reserved for cross-platform end-to-end tests. There is no runnable e2e suite checked in yet.
+This directory contains shared cross-platform Maestro flows for the Checkout Kit
+sample apps.
 
-Planned coverage:
+The current shared smoke flow verifies the happy path from a sample app cart
+into Shopify checkout and back to the app after completion. Each platform owns
+the small wrapper command that supplies its app id, cart bootstrap link, and
+platform-specific checkout field handling.
 
-- Swift checkout presentation and protocol lifecycle.
-- Android checkout presentation and protocol lifecycle.
-- React Native wrapper behavior.
-- Web component open/close and `checkout:*` events.
+## Run locally
 
-Until this directory contains test code, use the platform test suites and sample apps described in each platform README.
+Build and install the target sample app first, then run the matching Maestro
+command.
+
+From `platforms/react-native`:
+
+```bash
+pnpm e2e:ios
+pnpm e2e:android
+```
+
+From `platforms/swift`:
+
+```bash
+./Scripts/e2e_maestro_ios
+```
+
+From `platforms/android`:
+
+```bash
+./scripts/e2e_maestro_android
+```
+
+## Files
+
+- `config.yaml` configures Maestro for shared platform behavior.
+- `shared/checkout-smoke.yaml` contains the cross-platform checkout smoke flow.
+
+## Scope
+
+This smoke flow is intended to catch regressions in the sample app integration
+surface: cart bootstrap, checkout presentation, checkout completion, and return
+to the sample app. It is not a replacement for checkout-web's own browser-based
+test coverage.

e2e/config.yaml

@@ -0,0 +1,4 @@
+platform:
+  ios:
+    # Lets Maestro inspect elements presented inside iOS checkout modal views.
+    snapshotKeyHonorModalViews: true