agave 4.3 changes

[smcio]

Various changes for Alpenglow’s upgrade to Agave 4.3. Some additional fixes for better handling of state and decision handling. In brief, these were:

• updated Mithril’s Alpenglow feature IDs and derived accounts to match the regenesis’d Alpenglow cluster (agave 4.3)

• ported Votor networking to the Agave's 4.3 protocol: alpenglow-v1, QUIC datagrams, updates to the vote wire format.

• added proper validator identity checks to votor connections, with vote rank now being derived from the authenticated peer instead of being sent in the message as before

• reworked votor peer discovery and epoch transitions so that current, trailing and upcoming validator sets are handled correctly, including proactive connection and reconnection.

• fixed up the validator set startup ordering so votor does not start before the required epoch stake data is available

• fixed slow-final certificates to reward the union of notarize and finalize signers, including notarize-only validators

• fixed the Alpenglow epoch boundary rewards calculation. EpochRewards.TotalRewards now uses the inflation budget recorded at the start of the rewarded epoch, as Agave 4.3 does, instead of recalculating it after VAT burns

• fixed up snapshot importing so truncated or malformed appendvec blobs fail cleanly and more clearly

• added proper error and panic propagation from the parallel snapshot index builders

• improved replay so it waits for pending state saves instead of hitting the 512-slot limit and stopping.

• tightened fork handling around certified skips and late blocks, so that a late speculative branch cannot replace or persist over something already certified

• improvements to skipped slot tracking & handling that occasionally popped up

• fixed replay so that we wait for pending state saves instead of hitting the 512-slot limit and stopping.

• regression tests for the snapshot importer, genesis transitions, votor, certificate signer handling, and others