* op-node: sync start update func signature, port over tests from safe-head-fix pr

* op-node: sync start now starts with current heads by label

* op-node: single loop find-heads

* op-node: sync - clean up go doc

* op-node: use sync fn in engine queue

* op-node: fix engine queue finalization test

* op-node: sync off-by-one fix

* op-node: fix highest l2 block with canon origin, need to reset when l1 reorg

* op-node: handle non-standard safe/finalized not found errors

* op-node: sync start review fixes / comment typos

* op-node: seq window size check with l1 origin, update engine queue test with extra l1 origin, now that off by 1 fix applies properly to chains with multiple L2 blocks per L1 block

* op-node: start from parent block before seq nr 0

* Update op-node/rollup/sync/start.go
Co-authored-by: Joshua Gutow <jgutow@optimism.io>

* review fixes

* fix lint
Co-authored-by: Joshua Gutow <jgutow@optimism.io>
Co-authored-by: Matthew Slipper <me@matthewslipper.com>

feat(ctb): tweak XDM storage layout

Tweaks the storage layout of the CrossDomainMessenger base contract to
reduce the number of changes with the existing system. The
L1CrossDomainMessenger has no storage diff after this PR.

feat(ctb): make StandardBridge vars immutable

chore: Upgrade foundry

Updates the StandardBridge to use immutable variables instead of state
variables. Primary reason for this change is to guarantee that the
storage layout will not be a problem during the upgrade. Plus, there's
really no reason why these variables shouldn't be immutable.

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

* op-node: Add heartbeater

* Update op-node/heartbeat/service.go
Co-authored-by: Joshua Gutow <jgutow@optimism.io>

* imports
Co-authored-by: Joshua Gutow <jgutow@optimism.io>

Use `hardhat compile` so that it ensures that the artifacts
used by the generator are up to date

Moves the `GovernanceToken` into `contracts-bedrock`
so that its artifact can be easily inspected. This
is the first step in deleting `contracts-governance`.
The other files should be moved to `contracts-periphery`.

Every L2 predeploy that has `Semver` must be built so that it's
immutables are handled, even though they are hardcoded in the
bytecode.
Co-authored-by: Matthew Slipper <me@matthewslipper.com>

fix(ci): properly publish hardhat-node

l2geth: add block tag to `eth_estimateGas`

Fix: expired Discord link

* op-node: Add additional command to generate L2 configs

This command will be used in bedrock-regentool to replace the old hardhat scripts.

* fix linter

Release op-* v0.8.6

* op-chain-ops: Allow configurable dev accounts

* Set difficulty to zero

* Add tests

* chore: Upgrade op-geth

* Add forgotten params

* Update chain ops

Copies the implementation from upstream
https://github.com/ethereum/go-ethereum/blob/389021a5afd01147c851870c693ded8760e6a08c/internal/ethapi/api.go#L1149

MetaMask requested that we use ethers submodules instead of importing
the entire ethers package. Relatively straightforward change.
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

Fixes two contracts in contracts-periphery to use the correct import
paths. Also modifies the contracts package to copy contracts into the
root directory on every build, not just before publish. This resolves
the issue where the contracts package could not be properly used within
the monorepo.
Co-authored-by: Mark Tyneway <mark.tyneway@gmail.com>

Last unwrapped errors

These where missed in local lints but when a full lint was run these
popped up.

* op-node: Properly wrap errors

* op-proposer: Properly wrap errors

* Update linters to use errorlint

This includes a hack with golangci-lint to disable the assertion
and comparison check in errorlint but to retain the errorf lint.

In the the future the assertion lint could probably be fixed, but
the comparison lint may be overactive with certain cases.

* op-node: Properly return error on bad hex data

* Add forgotten err to Pub2PeerID
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

* op-node: Switch to 128 bit channel ID & block # timeout

This PR removes the 256 bit channel ID + timestamp. With the timestamp
being removed, the channel timeout is now done with block numbers.

* Update specs/derivation.md

* fix system test config

* op-node: Fix OPB-01

`(*ExectionPayload).UnmarshalSSZ()` fails to properly validate the `transactionsOffset` and `extraDataOffset` values, allowing a malicious actor to crash multiple op-nodes by gossiping a P2P message containing a specially crafted `SSZExecutionPayload`.

* lint

- OPB-05: Puts the signature verification before further unmarshaling to guard against mal-formed payloads.
- Adds a minimum size check to the payload decoding to ensure we always have at least a signature and a payload available.