chore: port-to-v6 rolling port

[AztecBot]

Rolling integration PR for changes labelled port-to-v6 on next. Each merged source PR is cherry-picked onto cb/port-to-v6 as its own commit, keeping (#N) in the title.

Ported

• #25589 chore: blobs and docs (pick of the merge commit, -m 1, applied without conflicts, plus one fix(port) commit)
  • All eight files end up identical to next at 86d0021, as do the blob and rollup-lib crates and the whole l1-contracts directory.
  • It adds two labs patches, which keep their next numbering:
    • 0006-fix-blob-lib-bind-checkpoint-boundaries-into-the-blo.patch (yarn-project/blob-lib, a test fixture path and the L1 publisher integration test)
    • 0007-docs-aztec-nr-private-log-fields-past-the-log-s-leng.patch (a doc comment in aztec-nr's private_context.nr)
  • Every file those two patches touch has the same pre-image blob on the v6 labs pin a0d73c0aed as the patch expects.
  • The fix(port) commit updates labs patch 0001-test-pin-testnet-compatibility-to-the-v6-kernel-VK-t.patch to the VK tree root v6 builds with this change.

Protocol impact

• The blob commitments hash now binds checkpoint boundaries: each commitment is hashed with a one-byte flag that is 0x01 for a checkpoint's first blob and 0x00 otherwise. The change is made in three places that have to agree:
  • L1: BlobLib.calculateBlobCommitmentsHash
  • circuits: the blob crate (blob_batching.nr, the accumulator ABIs), consumed by the rollup circuits
  • node: yarn-project/blob-lib, through labs patch 0006
• This changes the rollup circuits, so the VK tree root that v6 builds moves:
  • from 0x1032cbb2f61a9c1151370ebc35c8ea20d1a726e3388eb94e84291c2b2fecb5d3 (pinned on v6 since chore: port-to-v6 rolling port #25587)
  • to 0x031139abb5b9f51ca0e55a6e2022d567029f50acc9428506f05c91ae27e7f75d (taken from this PR's failing CI run on b2cd9f3f), which is what labs patch 0001 now pins
• The testnet deployed from v6 has root 0x2d89003cc2dc62b06f07d83d3635c66c63fc43668369d30e7ee516f908ee10e3; v6 has not matched it since chore: port-to-v6 rolling port #25575. The re-pin follows the decision recorded on chore: port-to-v6 rolling port #25549 (a breaking circuit change ported to v6 re-pins testnet in the same PR).
• The protocol contracts hash and the genesis root are unchanged; those two assertions passed on b2cd9f3f.
• The L1 change takes effect only on a rollup deployed from this code. A node built from this branch computes the new hash, so it does not agree with a rollup deployed before it.

Testing

• CI3 on b2cd9f3f (before the re-pin): testnet_compatibility.test.ts › "has expected VK tree root" was the only failure in the fast run, which covers the blob and rollup circuit tests, the new blobCommitmentsHash.t.sol forge test and the labs blob-lib tests.
• ./labs-patches/bootstrap.sh check: the series (0001, 0006, 0007, 0010) applies cleanly to the labs pin a0d73c0aed. Patch 0001 was produced with bootstrap.sh apply / export.
• No circuits or L1 contracts were built locally (no nargo and no pinned solc in the port environment); the re-pinned test runs on this PR's CI.

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Created by claudebox · group: slackbot · Slack thread