[example] Add example for Swift Service Lifecycle

[sebsto]

Now that task cancellation works, re publishing this PR with a new example for Swift Service Lifecycle

[Copilot]

Pull Request Overview

This PR adds a comprehensive example demonstrating Swift Service Lifecycle integration with AWS Lambda and PostgreSQL RDS, along with minor fixes to Docker command references and local server implementation.

• Adds a complete ServiceLifecycle+Postgres example with AWS infrastructure setup
• Fixes Docker command references in format checking scripts
• Updates local server implementation to handle return values properly

Reviewed Changes

Copilot reviewed 18 out of 18 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
scripts/check-format-linux.sh	Fixed Docker command references from 'container' to 'docker'
Sources/AWSLambdaRuntime/Lambda+LocalServer.swift	Updated return type handling and error management in local server
Examples/Streaming/samconfig.toml	Added SAM configuration for streaming example
Examples/ServiceLifecycle+Postgres/*	Complete new example with PostgreSQL integration, infrastructure templates, and documentation
.licenseignore	Added .toml files to license ignore list
.github/workflows/pull_request.yml	Added new example to CI workflow

[Copilot]

The return type change from Result to Swift.Result<Result, any Error> appears to be a breaking change that could affect API consumers. This should be carefully considered for backward compatibility.

Suggested change

	) async throws -> Swift.Result<Result, any Error> {
	) async throws -> Result {

[adam-fowler]

So when does this function throw an error and when does it return the error as a Result?

[adam-fowler]

Out of interest what was causing the shutdown error, that you are ignoring now

[sebsto]

So when does this function throw an error and when does it return the error as a Result?

when the user types CTRL-C to stop the server and the server is part of a service lifecycle group

Out of interest what was causing the shutdown error, that you are ignoring now

The reported error is Channel I/O by an attempt to read/write on a closed channel.
I don't know the root cause.

Because this happens on the local server, just used for testing, and at the time of shutdown. I think it's sfe to ignore the error and let the app terminate.

[adam-fowler]

Would it not be better to make it clear what the issue is. Instead of returning a Result. Wrap the whole function in a

do {
    contents of LambdaHTTPServer.withLocalServer
} catch is ChannelIOError /* whatever the error is */ {
     // comment detailing issue, so it can be looked into later
}

[sebsto]

OK, done

[sebsto]

@adam-fowler This is a new example.
I made a tiny change to the local HTTP server to avoid a crash + backtrace on CTRL-C, let me know if you think there is a more elegant way to solve that. (the root cause is a Channel I/O error on CTRL-C, looks like we still attempt to send data on a closed channel)

The rest is "just" a PostgreSQL + service lifecycle example. I provide a SAM template to setup the database in a secure way (private network, restrictive security groups, password stored in secret manager)

[adam-fowler]

So when does this function throw an error and when does it return the error as a Result?

[adam-fowler]

Out of interest what was causing the shutdown error, that you are ignoring now

[sebsto]

@adam-fowler Thank you for the initial review. I added PreludeService and answered your questions