add sso flow

[strehle]

No description provided.

[Copilot]

Pull Request Overview

This PR adds SSO (Single Sign-On) flow functionality to enable users to open a new web session in IAS using an SSO token. The implementation includes a new command handler that constructs a SAML SSO URL and opens it in the user's default browser based on their platform.

Key changes:

• Added a new HandleSsoFlow function to process SSO tokens and launch browser-based authentication
• Introduced sso command and related flags (-redirect_uri, -sso) for SSO flow configuration
• Added support for resource parameter override in token-exchange flows

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 6 comments.

File	Description
pkg/client/client.go	Implements the core SSO flow handler with platform-specific browser opening logic
openid-client/openid-client.go	Adds CLI command and flags for SSO functionality, integrates SSO flow into main execution path
README.md	Documents the new SSO command and related flags

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[Copilot]

Pull Request Overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

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[Copilot]

Pull Request Overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

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