Provide a local preview harness for Solidity field renderers

## Problem

JavaScript code projects have a local preview workflow, but custom Solidity image/attributes renderers require Forge tests followed by a testnet deployment to inspect realistic token, seed, and parameter output.

## Desired outcome

Provide a local renderer preview that exercises the deployed interface shape without spending testnet funds.

## Acceptance criteria

- Accept a renderer build/artifact plus representative token id, seed, and parameter inputs.
- Execute the actual renderer interface in a local EVM context.
- Decode and display the declared content type and returned bytes.
- Surface reverts clearly and avoid pretending the harness proves production gas viability.
- Document how generated renderer scaffolds use the preview.

Start by locating the existing local preview workflow for JavaScript projects and the generated renderer scaffolds mentioned in the issue. Trace how renderer artifacts and token, seed, and parameter inputs are represented, then verify that the preview executes the interface locally, displays content type and returned bytes, reports reverts, and documents scaffold usage.

Written by the indexing model from the issue text.