Add CI that tests the SES, SQS and SNS examples

[HarshCasper]

The repo had no CI and no tests, and the SQS sample order could not be processed.

Fixes:

• sqs/sampleData/order.json sent items with name, but OrderManager reads itemDetail. The DynamoDB document client rejected the undefined value, so make test-order failed before anything reached the queue. The data now uses itemDetail.
• OrderManager now keeps an item's itemId when the order gives one. The sample's IDs (ITEM-101, ITEM-223) are the ones the README's failure rules describe.
• sqs gets esbuild as a dev dependency, so cdk deploy bundles locally instead of in Docker.
• The sqs and sns Makefiles put node_modules/.bin on PATH. lstk cdk runs cdk from PATH, so make deploy failed with "cdk not found in PATH" without a global install.
• ses/Makefile resolved the topic ARN from aws configure get region and fell back to plain aws without the LocalStack endpoint. It now uses lstk aws sns create-topic, which returns the existing topic.
• sns/README.md: phone numbers in E.164 format, a placeholder instead of a real API ID, and Content-Type: application/json on the filter examples. Without it, LocalStack's API Gateway re-encodes the body as form data and the Lambda cannot parse it.

Tests, run with make test in each example:

• ses: runs make setup-all, checks the sender is verified, the configuration set exists, and the email subscription is confirmed. Sends a text and an HTML email and reads both back from /_aws/ses.
• sqs: submits the sample order under a unique ID, checks the order total, then waits until ITEM-223 is FAILED through the DLQ, ITEM-101 is PROCESSED or FAILED, and the other items are PROCESSED.
• sns: publishes four events through the API, checks each subscriber Lambda's logs only contain the events its filter policy allows, that ops-alerts published to its topic, and that SMS messages were sent. Also checks an invalid event type returns 400.

The SES test does not read back the event destination. On LocalStack, describe-configuration-set with eventDestination returns an empty EventDestinations list after a successful create-configuration-set-event-destination, and sesv2 get-configuration-set-event-destinations is not implemented. make setup-all still fails if the create fails.

New workflow runs the three examples in a matrix: start LocalStack with lstk, deploy the CDK stack for sqs and sns, then make test.

Verified by CI.

https://claude.ai/code/session_01DZfDmzUBPqNAu3yFKyfCNM