Propose sequencing header

[prototypo]

Rationale

Ethereum fragmentation via L2 sequencing silos has arguably been a primary cause of ETH’s divergence from BTC since the significant rise of L2s in the last two years. This is because the value of transactions at the L2 layer has devalued the value of the L1; in other words, we currently risk the market taking the L1 layer for granted, which would create an existential threat to the proof of stake consensus system. Thus, this proposal suggests that new ERCs should be required to state whether and how they align with the goal of Shared Sequencing/Universal Synchronous Composability. Such mandatory statements during the ERC proposal process can assist both editors and Core Devs with the review of new ERCs in relation to the Ethereum roadmap.

Summary of changes:

• Add fragmentation status metadata and a description of its use to the EIP Header Preamble.
• Add review responsibility to EIP editor to ensure fragmentation status metadata is present.

Notes:

• The only ERC of type: Meta is currently EIP-1. EIPs have made more heavy use of Meta documents than ERCs, with 36 Meta EIPs so far. Therefore, this change is proposed to EIP-1 instead of introducing a new Meta ERC.
• The use of other as a possible value for the sequencing header is considered suboptimal, but was included to future-proof the proposal in the case that other sequencing solutions beyond based and shared become available. Alternatives to this approach would be very welcome.

Dependencies:

• If accepted, this change would require an update to https://github.com/ethereum/EIPs/blob/master/eip-template.md or a fork of that template to the ERC repository.
• If accepted, this change would require either the same change to be made to the version of EIP-1 in the EIPs repository, or the creation of a fork of EIP-1 in the ERC repository.