Msg Validation Rules for the Gloas Fork (SIP-94)

[iurii-ssv]

Overview

This PR adds the message validation rules for the Gloas fork (ePBS), per SIP-94 §7, as a new section of Rules.md. Every existing rule keeps applying. Each row in the new section is marked as new, or as modifying an existing rule.

• New roles: RolePTCAttester (7), with PTCAttesterPartialSig, and RoleProposerPreferences (8), with ProposerPreferencesPartialSig and RequestAuthPartialSig. Both are validator-scoped, and consensus messages are rejected for both.
• Fork gates:
  • PTC and proposer-preferences messages are rejected at pre-fork slots;
  • validator registrations are rejected at Gloas slots;
  • validator registrations are ignored at any slot once the wall-clock epoch is past the fork.
• Entry limits: a validator-role packet carries one entry, except 1–8 for RequestAuthPartialSig and up to 2 for the proposer's post-consensus packet at Gloas slots (the block root and the execution-payload envelope root). Every entry carries the same validator index.
• Proposer preferences:
  • exempt from the slot-advance rule;
  • accepted from the start of epoch epoch(slot) - MIN_SEED_LOOKAHEAD until 2 slots after the proposal slot;
  • budgeted per signer and slot at 4 distinct preference roots and 8 distinct request-auth roots. A repeated root, or one over budget, is ignored rather than rejected.
• PTC attestation: one partial per slot, a 3-slot lateness TTL, and 2 duties per epoch.
• Duty-assignment checks for both roles, tolerating a not-yet-fetched or stale duty view, plus state retention for the whole acceptance window.

The rules match the node implementation in ssvlabs/ssv#2901. This follows up on the SIP-94 thread.

Notes

• Independent of Msg Validation Rules for Boole Fork #2 (Boole): Gloas activates while Boole is dormant, so this section is written against the current rules. It only adds lines, and it merges cleanly with Msg Validation Rules for Boole Fork #2.
• Error classification: the existing error block declares ErrTooManyPartialSignatureMessages without reject: true, while its table row rejects. The new rows follow the table, and so does the node. I left the declaration alone so as not to conflict with Msg Validation Rules for Boole Fork #2's rewrite of that block.