fix(satp-hermes): ERC-6909/ERC-721 uniqueDescriptor truncates large uint256 token IDs

[lukacoff]

What happened?

Description

UniqueTokenID (the branded type behind Asset.uniqueDescriptor,
used for ERC-6909 multi-token type IDs and ERC-721 NFT IDs) is
currently branded as number:

https://github.com/hyperledger-cacti/cacti/blob/main/packages/cactus-plugin-satp-hermes/src/main/typescript/cross-chain-mechanisms/bridge/ontology/assets/asset.ts

Since on-chain token IDs are uint256, any value above
Number.MAX_SAFE_INTEGER silently loses precision when passed through
Number(), corrupting the token ID used for cross-chain asset
transfer — e.g. in the bridge execution layer's LOCK/UNLOCK paths and
in besu-leaf.ts / ethereum-leaf.ts's getAsset().

Proposed fix

Rebrand UniqueTokenID as bigint and remove the Number()
conversions on the bridge execution layer / EVM leafs, updating the
affected tests accordingly.

Expected behavior

Asset uniqueDescriptor / tokenId values representing on-chain uint256 token IDs (ERC-6909 type IDs, ERC-721 NFT IDs) should preserve full precision throughout the bridge — from the wire format (proto string) through the internal Asset representation to the contract call — even for values larger than Number.MAX_SAFE_INTEGER (2^53 - 1).

Steps to reproduce

1. Note that UniqueTokenID is defined as Brand<number, "UniqueTokenID"> in packages/cactus-plugin satp-hermes/src/main/typescript/cross-chain-mechanisms/bridge/ontology/assets/asset.ts
2. In besu-leaf.ts / ethereum-leaf.ts's getAsset(), the on-chain uint256 token id (returned as a string) is converted like this: uniqueDescriptor: Number(token.amount) as UniqueTokenID
3. Reproduce the precision loss directly in a Node REPL:
   const onChainTokenId = "9007199254740993"; // 2^53 + 1
   console.log(Number(onChainTokenId));
   // -> 9007199254740992 (wrong: lost the last bit of precision)
4. The same pattern (Number(...) as UniqueTokenID) is used in satp-bridge-execution-layer-implementation.ts for the LOCK/UNLOCK paths of NonFungibleAsset, silently corrupting the token id used to identify the asset being locked/unlocked cross-chain.

Cacti version or commit SHA

8747ce1

Environment

node -v && uname -srm
v24.18.0
Linux 7.0.0-30-generic x86_64

Affected package(s) / connector(s)

No response

Logs or stack traces

Additional context

No response