Attachment client improvements

[xTEddie]

• Attachment client improvements on widgets hosted on whitelisted URLs
• Attachment client multi-region support on non-whitelisted URLs

[Copilot]

Pull Request Overview

This PR enhances the AMS attachment client with support for whitelisted and region-based URLs, configurable via new internal flags, and refactors widget snippet URL parsing.

• Introduced AMSClientUtils with whitelistedUrls, shouldUseFramedMode, and retrieveRegionBasedUrl
• Added disableAMSWhitelistedUrls & disableAMSRegionBasedUrl config flags and wired them into createAMSClient
• Extracted widget snippet base URL parsing into setWidgetSnippetBaseUrl and updated loading logic
• Simplified Jest node setup and added tests for new utilities

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/utils/AMSClientUtils.ts	New utility functions and URL whitelist array
src/core/ChatSDKConfig.ts	Added internal config flags; minor doc comment update
src/OmnichannelChatSDK.ts	Integrated new AMSClientUtils, added widgetSnippetBaseUrl handling, and updated AMS client calls
jest.setup.node.js	Removed legacy JSDOM mocks, retained global.self mock
tests/utils/AMSClientUtils.web.spec.ts	Tests for new utils in browser environment
tests/utils/AMSClientUtils.node.spec.ts	Tests for new utils in Node environment
tests/external/ACSAdapter/createFileScanIngressMiddleware.spec.ts	Minor window mock addition
CHANGELOG.md	Updated changelog entry for attachment client improvements

Comments suppressed due to low confidence (1)

src/core/ChatSDKConfig.ts:36

• [nitpick] The flag name disableAMSRegionBasedUrl is inconsistent with disableAMSWhitelistedUrls (singular vs plural). Consider renaming for consistency, e.g., disableAMSRegionBasedUrls.

disableAMSRegionBasedUrl?: boolean;