add a text chat example

[sebsto]

Issue #, if available:

Description of changes:

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[Copilot]

Pull Request Overview

This PR adds a new interactive text chat example using the Swift BedrockService, complete with build configuration and CI integration.

• Implements a streaming CLI example that maintains conversation history.
• Introduces a standalone Swift package and .gitignore for the example.
• Updates the GitHub Actions workflow to include text_chat in the examples matrix.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 4 comments.

File	Description
Examples/text_chat/Sources/TextChat.swift	New CLI example for streaming text chat with conversation history
Examples/text_chat/Package.swift	Package manifest for building the TextChat executable
Examples/text_chat/.gitignore	Workspace and build artifact ignores for the example
.github/workflows/pull_request.yml	Adds text_chat to the CI job’s examples list

Comments suppressed due to low confidence (1)

Examples/text_chat/Sources/TextChat.swift:98

• [nitpick] Consider renaming 'MyError' to something more descriptive like 'TextChatError' to clarify its purpose.

enum MyError: Error {

[Copilot]

Typo in comment: 'stateles' should be 'stateless'.

Suggested change

	// ConverseRequestBuilder is stateles, it doesn't keep track of the history
	// ConverseRequestBuilder is stateless, it doesn't keep track of the history

[Copilot]

Force-unwrapping 'request' may cause a runtime crash if it's nil; consider using a guard let to safely unwrap or refactor the logic to avoid optionals here.

Suggested change

	request = try ConverseRequestBuilder(from: request!)
	guard let existingRequest = request else {
	throw MyError.incorrectModality("Request is unexpectedly nil")
	}
	request = try ConverseRequestBuilder(from: existingRequest)

[Copilot]

Force-unwrapping 'request' here may crash if nil; ensure it's non-nil with a guard or unwrap earlier.

Suggested change

	let reply = try await bedrock.converseStream(with: request!)
	guard let unwrappedRequest = request else {
	throw MyError.incorrectModality("Request is unexpectedly nil")
	}
	let reply = try await bedrock.converseStream(with: unwrappedRequest)

[Copilot]

[nitpick] Consider using 'logger.error' instead of 'print' for error messages to maintain consistent logging and support structured logs.

Suggested change

	do {
	try await TextChat.run()
	} catch {
	print("Error:\n\(error)")
	var logger = Logger(label: "TextChat.Main")
	do {
	try await TextChat.run()
	} catch {
	logger.error("Error:\n\(error)")