Improve CSM Authorization v2.x concepts and configuration docs for v1.15 and v1.16

[mgandharva]

Description

Improve CSM Authorization v2.x concepts and configuration documentation: clarify token lifecycle, secrets reference, certificate validation settings, ingress exposure for Kubernetes/OpenShift, and remove redundant sections across all versioned docs.

GitHub Issues

List the GitHub issues impacted by this PR:

GitHub Issue #

Checklist:

• Have you run a grammar and spell checks against your submission?
• Have you tested the changes locally?
• Have you tested whether the hyperlinks are working properly?
• Did you add the examples wherever applicable?
• Have you added high-resolution images?

Updated image

[github-actions]

Test Results

79 tests   79 ✅  4s ⏱️
 3 suites   0 💤
 1 files     0 ❌

Results for commit 5874ee7.

♻️ This comment has been updated with latest results.

[rajkumar-palani]

One minor comment related to "karavi-config-secret".

[prablr79]

LGTM

[alikdell]

This also need go to main and notify Ray so that he incorporate the changes for future doc or have this documented in new doc repo, either way this information need to go to Ray so that this changes are part of future doc releases

[mgandharva]

This also need go to main and notify Ray so that he incorporate the changes for future doc or have this documented in new doc repo, either way this information need to go to Ray so that this changes are part of future doc releases

Sure, I'll put the PR for main