batch transactions for delegated accounts to avoid in-flight tx limit

[cloudonshore]

Motivation

Ethereum nodes (reth, geth) enforce a limit of 1 pending transaction for EIP-7702 delegated accounts. When a swap or bridge requires token approval, the bridge-status-controller submits approve and trade as two separate transactions. The second transaction gets rejected by the node with "in-flight transaction limit reached for delegated accounts", causing the swap/bridge to fail.

Related: MetaMask/metamask-mobile#25595

Description

This PR detects EIP-7702 delegated accounts and routes them through the existing batched transaction path (previously only used for smart transactions and gasless 7702 quotes), combining approve + trade into a single atomic transaction.

Changes

@metamask/transaction-controller

• Expose isAtomicBatchSupported as a messenger action so other controllers can check whether an account is delegated to a supported smart contract
• Register the action handler and export the type

@metamask/bridge-status-controller

• Add TransactionControllerIsAtomicBatchSupportedAction to AllowedActions
• Before transaction submission, call isAtomicBatchSupported to detect delegated accounts
• Add isDelegatedAccount as a third condition (alongside isStxEnabledOnClient and gasIncluded7702) for entering the batch transaction path
• Pass isDelegatedAccount through to getAddTransactionBatchParams so that disable7702 is set to false for delegated accounts — enabling 7702 batching with user-paid gas (not just gas-sponsored)
• Hoist isDelegatedAccount outside the #trace callback so it's accessible in the isNonBatchEvm check, ensuring batch transactions from delegated accounts are properly recorded in bridge status history
• Extend findAndUpdateTransactionsInBatch to handle TransactionType.bridge and TransactionType.bridgeApproval in the 7702 matching logic (previously only handled swap/swapApproval), fixing transaction lookup for bridge operations from delegated accounts
• Skip undefined entries in txDataByType iteration to prevent bridge transactions from being incorrectly retyped as swaps

Key design decisions

• Batching != gas sponsorship: These are orthogonal features. Delegated accounts need batching to avoid the in-flight limit, but can still pay their own gas. The disable7702 flag is now false when either gasIncluded7702 is true OR the account is delegated.
• Graceful fallback: The delegation check is wrapped in a try/catch that defaults to false, so if isAtomicBatchSupported fails for any reason, the transaction falls back to the standard (non-batch) path.

References

• reth in-flight limit: https://github.com/paradigmxyz/reth/blob/main/crates/transaction-pool/src/pool/txpool.rs

Changelog

@metamask/transaction-controller

• Added: TransactionControllerIsAtomicBatchSupportedAction type export
• Added: Messenger action handler for isAtomicBatchSupported

@metamask/bridge-status-controller

• Fixed: Delegated accounts (EIP-7702) now use batched transactions to avoid in-flight transaction limit
• Fixed: Bridge transaction types now properly matched in 7702 batch path (findAndUpdateTransactionsInBatch)
• Fixed: Delegated account batch transactions now recorded in bridge status history
• Fixed: Undefined tx type entries no longer cause swap/bridge mistyping in batch matching

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed
• I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them

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Note

Medium Risk
Changes the EVM swap/bridge submission path to conditionally batch transactions for EIP-7702 delegated accounts and adds a new required messenger permission/action, which could affect transaction creation, gas handling, and history recording if miswired.

Overview
Delegated (EIP-7702) accounts are now routed through the existing atomic batch path so approval + trade are submitted as a single batch to avoid delegated-account in-flight limits.

BridgeStatusController now calls TransactionController:isAtomicBatchSupported (new messenger action) to detect delegated accounts, records batched delegated txs in history, and updates 7702 batch post-processing to correctly match/retag bridge + bridgeApproval types (and skip undefined type entries).

Gas handling for batched 7702 flows is refined: gas fields are omitted only when gas is sponsored (gasIncluded7702), while delegated-account batching keeps 7702 enabled but still includes user-paid gas fields when not sponsored; tests/snapshots and changelogs are updated accordingly.

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[micaelae]

Can you mark this as a breaking change since the clients will need to add the new action handler permissions?

[cloudonshore]

Done. Just to double check, do you think this is the ideal pattern? I could also detect whether the account is delegated directly in bridge-status-controller (via eth_getCode) to avoid the breaking change, but didn't want the code duplication.

[micaelae]

I prefer reusing TransactionController's handler too so this looks good to me