Allow for prompt=select_account in native flows

[sameerag]

Native flows currently are never called directly if prompt=select_account. Add support for the same.

PS: prompt=create is still in discussion, will add a new PR if we need to account for the same or *if we can remove the prompt related code altogether.

[Copilot]

Pull Request Overview

This PR allows the prompt=select_account parameter to be used in native authentication flows through the platform broker (WAM). Previously, this prompt value was blocked and would cause native flows to fall back to web-based authentication.

Key changes:

• Enable select_account prompt in native flows by adding it to the allowed prompt values
• Update test cases to verify that select_account now works with native flows instead of falling back to web flows
• Add sample application testing buttons for different prompt values including select_account

Reviewed Changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
lib/msal-browser/src/interaction_client/PlatformAuthInteractionClient.ts	Added SELECT_ACCOUNT to allowed prompt values in native flow validation
lib/msal-browser/src/controllers/StandardController.ts	Added SELECT_ACCOUNT to platform broker compatibility check
lib/msal-browser/test/interaction_client/PlatformAuthInteractionClient.spec.ts	Updated tests to verify select_account works with native flows and moved create prompt test
lib/msal-browser/test/app/PublicClientApplication.spec.ts	Updated tests to verify native flows are used instead of web fallback for select_account
samples/msal-browser-samples/VanillaJSTestApp2.0/app/wamBroker/*.js	Added test functions and UI buttons for testing different prompt values
samples/msal-browser-samples/VanillaJSTestApp2.0/server.js	Updated certificate paths from placeholder to relative paths
samples/msal-browser-samples/VanillaJSTestApp2.0/app/wamBroker/authConfig.js	Changed authority from specific tenant to common endpoint