feat: add ERC-1271 support for smart wallets

[coffee-the-dev]

Summary

This PR adds smart-wallet compatibility across the Abstract MPP flows and updates the stream channel defaults to the newly deployed
contract on both Abstract testnet and mainnet.

What Changed

• Added ERC-1271-compatible charge verification on the server side.
• Added support for USDC.e ERC-3009 bytes signatures for charge settlement.
• Updated session voucher verification to support contract-wallet signatures.
• Updated AbstractStreamChannel to verify vouchers with SignatureCheckerLib instead of raw ECDSA recovery.
• Added test coverage for ERC-1271 payer settle/close flows.
• Updated MPP defaults to use 0x29635C384f451a72ED2e2a312BCeb8b0bDC0923c for AbstractStreamChannel on both testnet and mainnet.
• Wired the demo session flow to honor NEXT_PUBLIC_ESCROW_CONTRACT.

Why

Previously:

• charge assumed a 65-byte ECDSA signature and failed for smart wallets.
• session vouchers were verified with ECDSA.recover, so ERC-1271 wallets could not sign directly as the payer.
• The repo defaults still pointed at the older stream channel deployment.

This PR fixes those gaps so AGW / ERC-1271 wallets can use both charge and session flows, assuming the updated stream channel
deployment is used.

Contract / Address Updates

• AbstractStreamChannel:
  • 0x29635C384f451a72ED2e2a312BCeb8b0bDC0923c on Abstract testnet
  • 0x29635C384f451a72ED2e2a312BCeb8b0bDC0923c on Abstract mainnet

[changeset-bot]

🦋 Changeset detected

Latest commit: bf5772b

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@abstract-foundation/mpp	Patch

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Project	Deployment	Actions	Updated (UTC)
mpp-abstract-mpp-demo	Ready	Preview, Comment	Mar 25, 2026 10:37pm

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PR Summary

High Risk
High risk because it changes signature verification and settlement paths for both server-side ERC-3009 charges and on-chain AbstractStreamChannel voucher validation, which are security- and funds-critical. Incorrect verification or ABI selection could enable failed settlements or acceptance of invalid authorizations.

Overview
Adds smart-wallet compatibility across Abstract payments by switching server-side signature verification to contract-aware verifyTypedData and supporting ERC-3009 bytes signatures when broadcasting transferWithAuthorization (falling back to v/r/s only for 65-byte ECDSA).

Updates AbstractStreamChannel to validate vouchers via SignatureCheckerLib (ERC-1271 compatible) and extends Foundry tests with an ERC-1271 mock wallet covering settle and close flows.

Refreshes default AbstractStreamChannel addresses to 0x29635C...0923c (docs + DEFAULT_ESCROW split per chain) and allows the demo to override the escrow contract via NEXT_PUBLIC_ESCROW_CONTRACT.

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