Support child array paths in interpolated intents

[shukudaidayo]

Summary

• Store joined rendered values for child array paths such as items.[].amount
• Preserve existing interpolation behavior for top-level array paths such as items.[]
• Add regression coverage for child-array interpolatedIntent placeholders with item-scoped token formatting

The interpolation code can stay unchanged because it already resolves placeholders from the renderedValues map.

Context

This was surfaced while testing the Ocarina ERC-7730 registry submission: ethereum/clear-signing-erc7730-registry#2598.

That descriptor uses an EIP-712 interpolatedIntent like:

"interpolatedIntent": "Authorize {tips.[].amount} tip"

The referenced field is formatted as tokenAmount using an item-scoped tokenPath such as tips.[].token.

Details

This updates array-path metadata tracking so rendered values are joined and stored under the full wildcard path:

• items.[]
• items.[].amount
• tips.[].amount

Top-level array fields still also store the joined value under the base path for compatibility.

Validation

• npm test
• npm run check:types
• npm run check:prettier
• npm run check:eslint