Add ERC: Stateful Fungible Token

[cc358]

Summary

Adds a new Standards Track (ERC) proposal: Stateful Fungible Token — an ERC-20
extension that maintains a per-holder, on-chain provenance lineage which updates
automatically on every transfer, while preserving full ERC-20 fungibility and
backwards compatibility.

Discussion thread: cc358/dna-standard#1

What it does

• Every holder carries a weighted set of ancestor addresses (a "lineage") whose
  weights sum to 100% (10000 bps) when the balance is non-zero.
• On each non-exempt transfer, the recipient's lineage is re-blended from its prior
  lineage and the sender's, weighted by the recipient's balance and the amount sent.
• Bounded by a depth cap (maxLineageDepth) and a dustThreshold, keeping per-transfer
  gas bounded and resisting 1-wei sybil/dust pollution.
• Mint/burn, the contract itself, and designated router/liquidity contracts (e.g.
  Uniswap V4 PoolManager) are exempt, so AMM swaps and vault flows don't pollute lineage.
• Adds only view functions (lineageOf, lineageDepth, ancestorWeight,
  maxLineageDepth, blendRatio, dustThreshold) plus a LineageUpdated event.
  No ERC-20 method signature, return value, or side effect is changed.

Motivation

ERC-20 (fully fungible, no history) and ERC-721 (full identity, no fungibility) sit at
opposite ends of a spectrum. Many on-chain primitives — reputation systems,
sybil-resistant airdrops, on-chain social graphs, lineage-based access control — need
both liquidity and provenance. By attaching provenance to the holder rather
than the unit, this standard preserves full ERC-20 fungibility (pools, swaps,
accounting all work unchanged) while making a wallet's history a queryable, composable
on-chain property.

Reference Implementation

A complete, tested reference implementation (OpenZeppelin ERC-20 base + Uniswap V4 hook
integration; property-based tests covering weight conservation, depth-cap eviction, dust
handling, and 1-wei sybil resistance) is available at:

https://github.com/cc358/dna-standard

EIP-1 checklist

• This is a Standards Track proposal, category ERC.
• Title and description follow the EIP-1 preamble format.
• Specification uses RFC 2119 keywords.
• Includes Abstract, Motivation, Specification, Rationale, Backwards Compatibility,
  Reference Implementation, Security Considerations, and Copyright (CC0).
• Fully backwards compatible with ERC-20.
• Open-source reference implementation linked above.
• discussions-to set: ERC Stateful Fungible Token — Discussion Thread cc358/dna-standard#1
• eip provisionally set to the PR number (1762); final number to be confirmed by an editor.

[eip-review-bot]

File ERCS/erc-1762.md

Requires 1 more reviewers from @g11tech, @jochem-brouwer, @samwilsn, @xinbenlv

[github-actions]

The commit b26a71e (as a parent of 9800375) contains errors.
Please inspect the Run Summary for details.

[cc358]

Withdrawing this draft for now; will revisit later. Apologies for the noise.