chore(vendors|approaches):add fairblock and update private payment approach

[YadlaMani]

What are you adding?

• Vendor/Protocol
• Enterprise Use Case
• Update to existing content
• Other

Description

Fairblock is a purpose-built confidential layer combining lightweight homomorphic encryption + ZK to enable confidential transfers for existing EVM assets, with public counterparty relationships and scoped selective disclosure.

Checklist

• I've checked this doesn't duplicate existing content
• All links work
• Info is accurate

[YadlaMani]

Removed the Purpose-Built Confidential Layer from this pr

[Meyanis95]

LGTM!

[YadlaMani]

@Meyanis95 whenever you get a chance, could you open the issue so we can continue the discussion there? I’ll follow up with a detailed response and address your questions in that thread.
Appreciate your time on this.

[Meyanis95]

Hey @YadlaMani, I think you're in the best position to write the issue.

I'd suggest writing it as a new ./pattern to add to the map. Ideally, the issue should motivate that this technical pattern isn't mapped yet, as well as describe it thoroughly in the proposed pattern card.

Also mention that once done, it could be approved as one of the building blocks for a proposed approach to the private payments use case.

Also, we're good to merge this PR, and the newly created issue could be addressed in a new one.

[YadlaMani]

@Meyanis95 thank you for clairfication.I will be working on the issue please merge this pr if everyting is good to go with this pr