Enhance Smart Contract Security with Pectra Upgrade

The Pectra upgrade enables EOAs to execute code per EIP-7702, invalidating tx.origin==msg.sender checks. EIP-7251 raises validator max effective balance to 2048 ETH and adds a consolidation contract. EIP-2537 adds BLS12-381 precompiles. EIP-2935 stores latest 8191 block hashes. EIP-7002 permits execution-layer-triggered withdrawals. EIP-7623 raises calldata gas cost, reducing max block size and impacting relays and wallets.