Exporter: accommodate Glamsterdam / ePBS (Gloas) duties — PTC attester, proposer preferences, envelope builder

[iurii-ssv]

Context

#2901 (ePBS / EIP-7732 / Gloas) introduces three new validator-scoped duties and wires them into SetupRunners, but the exporter only partially accommodates Gloas. This issue tracks the exporter follow-ups so an exporter node on a Glamsterdam network actually observes the new duties — today it silently drops them.

Scoped intentionally as a follow-up to #2901 (draft / devnet), not a blocker for it.

What already works (no action needed)

• Committee attestation on Gloas is handled in both exporter paths: Collector.decodeCommitteeVote (archive / ModeArchive) and CommitteeObserver.SaveRoots / saveAttesterRoots (legacy) decode gloas.GloasBeaconVote and derive the attester root from the payload-status index. Attester + sync-committee traces keep working.
• Proposer traces decode spectypes.ProposerConsensusData (from the boole-fork baseline).

The gap

The three new roles from ssvlabs/ssv-spec#632 are not handled by either exporter path:

Role	Message shape
RolePTCAttester	partial-sig only (PTCAttesterPartialSig)
RoleProposerPreferences	pre-consensus partial-sig (ProposerPreferencesPartialSig), lookahead broadcast
RoleEnvelopeBuilder	QBFT consensus over gloas.EnvelopeConsensusData + post-consensus partial-sig

Failure mode — graceful, but untraced:

• Archive path (operator/dutytracer/collector.go): non-committee roles route through toBNRole(), whose default returns "unexpected runner role". All three hit it → collect() returns the error → the message worker logs at Debug and drops the message (no custom error handler is registered; defaultErrHandler). The duties are not traced.
• Legacy path (protocol/v2/ssv/validator/committee_observer.go): getBeaconRoles returns nil for unmapped roles → silently ignored.
• Routing (operator/validator/controller.go, nonCommitteeValidatorTTLs) has no entries for the new roles either.

Scope / checklist

Whether to surface each of these in the exporter is partly a product decision (PTC and proposer-preferences are new concepts). Once decided:

• Collector (toBNRole + collect, operator/dutytracer/collector.go): add role handling. Note the envelope's FullData is gloas.EnvelopeConsensusData (not ProposerConsensusData), so proposal-data extraction needs a Gloas branch; PTC is partial-sig-only with a payload-attestation root that doesn't fit the existing BeaconVote-derived root logic.
• Model (exporter/model.go): new BeaconRole values fit the existing Role field, but the SSZ encoding is hand-maintained (exporter/model_encoding.go) — any struct change must be hand-edited. Confirm PTC / preferences map onto ValidatorDutyTrace or need a new shape.
• API (api/handlers/exporter/*): responses serialize Role.String(); add BeaconRole.String() cases (else "UNDEFINED") and query-param mapping in common_model.go.
• Routing (nonCommitteeValidatorTTLs): add TTLs for the new roles.
• Schedule filler (Collector.computeAndPersistScheduleForSlot): today only emits Attester / Proposer / SyncCommittee.

Related latent issue (independent of Gloas)

On main, toBNRole has no default case and silently returns the zero value BNRoleAttester for any unmapped role (boole-fork fixed this with a default that errors). Worth backporting the default guard to main independently, so a future new role can't be silently mis-recorded as ATTESTER.