Renames `label` to `round` since `Label` was renamed to `SigningProtocolRound`.
Adds some more context-less validation to transactions which used to be done
within the custom decode function which was simplified via the usage of borsh.
Documents in processor-messages where the Coordinator sends each of its
messages.
It's not only helpful (to easily check where Serai's view of the external
network is) but it's necessary in case of a non-trivial chain fork to determine
which blockchain Serai considers canonical.
We read from it but never writ to it.
It was used to check we didn't flag a block as notable after reporting it, but
it was called by the scan task as it scanned a block. We only batch/report
blocks after the scan task after scanning them, so it was very redundant.
It's only there to make the VariantSignid unique across Sessions. By localizing
the VariantSignid to a Session, we avoid this, and can better ensure we don't
queue work for historic sessions.
This is incomplete at this time. The logic is fine, but needs to be moved to a
distinct location to handle singular blocks which produce multiple Batches.
This technically has a TOCTOU where we sync an Epoch's metadata (signifying we
did sync to that point), then check if the Router was deployed, yet at that
very moment the node resets to genesis. By ensuring the Router is deployed, we
avoid this (and don't need to track the deployment block in-contract).
Also uses a JoinSet to sync the 32 blocks in parallel.
The caller is paid a fixed fee per unit of gas spent. That arguably
incentivizes the publisher to raise the gas used by internal calls, yet this
doesn't effect the user UX as they'll have flatly paid the worst-case fee
already. It does pose a risk where callers are arguably incentivized to cause
transaction failures which consume all the gas, not just increased gas, yet:
1) Modern smart contracts don't error by consuming all the gas
2) This is presumably infeasible
3) Even if it was feasible, the gas fees gained presumably exceed the gas fees
spent causing the failure
The benefit to only paying the callers for the gas used, not the gas alotted,
is it allows Serai to build up a buffer. While this should be minor, a few
cents on every transaction at best, if we ever do have any costs slip through
the cracks, it ideally is sufficient to handle those.
