Refactor to Viem and Remove Web3.js

[aniket866]

Move from this to this:

From: Using web3.js for contract interactions and utility functions.

• To: Using viem's publicClient and walletClient for all blockchain logic.

From: Reliance on the djed-sdk wrapper which bundles web3.js.

• To: Direct contract calls using viem with existing DjedABI and CoinABI JSON files.

From: web3.utils for handling big numbers and unit conversions.

• To: viem utilities like parseUnits and formatUnits.

@Zahnentferner

[Rav1Chauhan]

assign it to me .