Add JSON Web X Standards article

[xrissoula]

Description

This PR introduces documentation on JSON Web X (JWX) standards in Polykey, covering:

• The role of JWT, JWS, JWE, JWK, and JWA
• Why Polykey persists and transmits cryptographic data using JWX
• Comparisons with PKCS standards and alternative formats like PASETO

This document explains how Polykey leverages the interoperability of JSON-based cryptographic standards to enhance security and usability.

Issues Fixed

• Relates Create Article in Polykey-Docs Explaining the Polykey Elliptic Curve Article #119
• Clarifies how cryptographic keys and tokens are stored and transmitted in Polykey
• Provides a reference for developers working with JWT-based security models

Tasks

• 1. Added json-webx-standards.md to docs/reference/
• 2. Structured content for clarity and easy reference
• 3. Verified accuracy of technical claims

Final checklist

• Domain specific tests
• Full tests
• Updated inline-comment documentation
• Lint fixed
• Squash and rebased
• Sanity check the final build

[xrissoula]

This PR is closed in favor of #135