fix: viem adapter must treat raw byte messages as raw in verifyMessage

[gomesalexandre]

ViemUtils.verifyMessage decoded a Uint8Array message as UTF-8 text via TextDecoder before recovering the signer, instead of passing it through to viem as raw bytes.

Any binary message that isn't valid UTF-8 - notably an order digest hashed for the ETHSIGN signing scheme and passed via decodeSignatureOwner (packages/contracts-ts/src/settlement.ts) - gets silently mangled by the UTF-8 decode (replacement characters on invalid byte sequences) before being re-hashed with the personal_sign prefix, so the recovered address never matches the real signer.

ViemSignerAdapter.signMessage already handles the identical Uint8Array case correctly, using viem's { raw: bytes } message form (packages/providers/viem-adapter/src/ViemSignerAdapter.ts:37-48) - so signing an ETHSIGN order with the viem adapter works fine, but verifying/recovering its owner does not. ethers-v5/ethers-v6's verifyMessage handle a Uint8Array as raw bytes natively, so this drift was viem-only.

Fix

Use { raw: message } for the Uint8Array branch in ViemUtils.verifyMessage, matching the convention ViemSignerAdapter.signMessage already uses.

Test

Added packages/contracts-ts/tests/decodeSignatureOwner.test.ts: signs a test order with the ETHSIGN scheme across all three adapters (ethers-v5, ethers-v6, viem) using the real per-adapter signer, then recovers the owner via decodeSignatureOwner and asserts it matches the signer's address.

• Before this fix: fails only for the viem adapter (recovers an unrelated address instead of the real signer).
• After this fix: passes for all three adapters.

No existing test exercised decodeSignatureOwner for the ETHSIGN scheme, or the viem adapter's raw-byte message path, at all - this was a real, silent, untested correctness gap in owner/signature verification specific to the viem adapter.

Risk

Low - verifyMessage's string branch is untouched; only the Uint8Array branch changes, from an incorrect UTF-8 decode to the raw-bytes form viem itself documents and that the adapter's own signer already uses.

[coderabbitai]

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📥 Commits

Reviewing files that changed from the base of the PR and between 9057b6d and 23a44df.

📒 Files selected for processing (2)

• packages/contracts-ts/tests/decodeSignatureOwner.test.ts
• packages/providers/viem-adapter/src/ViemUtils.ts

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