EIP-5792 transaction batching for bridge operations

[dmytrotkk]

Right now every bridge action that needs multiple transactions (approve → transfer, wrap → transfer, etc.) sends them one at a time - each with its own wallet popup. EIP-5792 wallet_sendCalls lets us batch same-chain calls into a single wallet approval.

This applies to all multi-transaction steps that happen on the same chain within a single action. For example, in TransferERC20S2S.execute() the approve + transferToSchainERC20 are both on sChain1 — those can be batched. Same for WrapERC20S (approve + wrap), TransferERC20M2S (approve + deposit), etc.

What changes

• Extend viem wallet client with eip5792Actions()
• Add capability detection using wallet_getCapabilities — check if the connected wallet supports sendCalls and atomic execution
• For each action class that does approve + main call on the same chain: if wallet supports EIP-5792, use sendCalls with both calls in one batch; if not, fall back to current sequential behavior
• Track batch status via wallet_getCallsStatus
• Update transactions.ts (or create a new batchTransactions.ts) with a helper that takes an array of contract calls and routes through sendCalls or sequential fallback

Wallets with EIP-5792 support (as of March 2026): MetaMask, Coinbase Wallet, Rainbow, Trust Wallet.

Acceptance criteria

• MetaMask/Coinbase users see a single approval prompt for approve + transfer operations
• Wallets without EIP-5792 support still work via sequential transactions (no regression)
• All bridge routes work: S→S, M→S, S→M, wrap, unwrap
• Batch status tracking works (pending → confirmed)
• Error handling works correctly for both batched and sequential paths