✅ Issue 5: Integrate mint_and_claim_xzb – Mint xZB on L2

# ✅ Issue 5: Integrate mint_and_claim_xzb – Mint xZB on L2
## Summary:
Wire up the logic to mint xZB tokens on L2 after the proof is verified on L1.
Tasks:
Construct proof array from:

let recipient_felt = *proof.at(0);
let amount = *proof.at(1);
let nonce = *proof.at(2);
let time_stamp = *proof.at(3);

let mint_data = MintData { recipient: recipient_felt, amount, nonce, time_stamp };

Accept placeholder values if proof generation is not ready.

Call:

mint_and_claim_xzb(proof, commitment_hash, eth_address, r, s, y_parity)

Contract Info:
📍 L2 Bridge (Sepolia Starknet):[ 0x0123a4ce7980e3c4f5832af0735fc3beabdc157379e09aaf7c5e62dfa8c19427](https://sepolia.starkscan.co/contract/0x0123a4ce7980e3c4f5832af0735fc3beabdc157379e09aaf7c5e62dfa8c19427#read-write-contract-sub-write)