v0.2.0

Added

• ERC-1155 token (Erc1155, Burnable, MetadataUri, Supply, UriStorage).
• ERC-4626 “Tokenized Vault Standard” and ERC-20 Flash Mint extension.
• ERC-2981 on-chain royalties.
• ERC-20 Utils: SafeErc20.
• Finance: VestingWallet.
• Ownership: Ownable2Step.
• Token wrappers: Erc20Wrapper, Erc721Wrapper.
• Cryptography: Poseidon2 hash, Pedersen hash (Starknet params), Short-Weierstrass Curves.
• Math & utils: optimised Uint<_> big-integer ops (mul_div, shift-left/right, checked/unchecked add/sub).
• Constructors now supported across all contracts.
• All events derive Debug; contracts implement MethodError and IErc165.

Changed

• Keccak constants pre-computed at compile-time.
• Optimisations across contracts and crypto libraries.

Changed (Breaking)

• Stylus SDK ↑ to v0.9.0 (cargo-stylus ↑ to v0.6.0)
• Contracts refactored to new inheritance model.
• Interface IDs now returned by fn interface_id(); IErc165::supports_interface takes &self; Erc165 struct removed.
• Public state fields made private.
• Feature std removed from libraries.

Fixed

• Correct ERC-165 IDs for IErc721Metadata, IErc721Enumerable, etc.
• #[interface_id] macro now propagates super-traits correctly.
• Edge-cases in Merkle proofs, big-int overflows and re-entrancy bugs resolved.

Full Changelog: v0.1.2...v0.2.0.