chore(nightly): bump @aztec/* to 5.3.0-nightly.20260921

[AztecBot]

Nightly bump to 5.3.0-nightly.20260921.

Draft: the bump itself is complete, but build and test could not run — the Aztec toolchain (nargo) is not installable for this version because the upstream release job failed before publishing the install assets. Details below.

What changed

node scripts/update.js (auto-resolved v5 → 5.3.0-nightly.20260921), then yarn format:fix:

• 7 workspace package.json files
• .aztecrc (5.3.0-nightly.20260827 → 5.3.0-nightly.20260921)
• 4 Nargo.toml files under packages/contracts/aztec/noir/
• yarn.lock

yarn install resolved cleanly against the new pins — every @aztec/* npm package the repo depends on is published at this version.

Blocker: toolchain install assets were never published

The nightly tag run (aztec-packages actions/runs/35559978360) succeeded, but the release run it triggered failed:

• CI3 run 35560002059 → job ci → step x-release failed after 805s (ci.aztec-labs.com/56beee99b7874359, inner log 1789963860402636).
• Failure at 04:24:17 UTC: Failed after 3 attempts: do_or_dryrun npm install @aztec/prover-client@5.3.0-nightly.20260921 — npm error code ETARGET / notarget No matching version found.
• That package is published now (it was a registry-propagation race — the release's own post-publish verification outran npm), but the job had already aborted, so the toolchain assets and aliases were never written.

Consequences, as of 05:35 UTC (~85 min after the tag):

• https://install.aztec.network/5.3.0-nightly.20260921/install → 404
• https://install.aztec-labs.com/aliases/nightly and /aliases/v5-nightly → still 5.3.0-nightly.20260920

aztec-up fetches every version asset from $INSTALL_URI/<version>/install, so there is no other route to a matching nargo/bb for this nightly. Using 20260920's nargo against 20260921's aztec.nr was rejected as a source of bogus results.

What was run

Step	Result
node scripts/update.js	✅ pins + yarn install clean
yarn format:fix	✅ no drift (amended into the bump commit)
yarn build	❌ @aztec-kit/contracts-aztec#build → Error: spawn nargo ENOENT
yarn test	⛔ not run — depends on the contracts build

The npm-shipped CLI (node_modules/.bin/aztec) does report 5.3.0-nightly.20260921, but aztec compile shells out to nargo, which only ships in the install bucket.

To unblock

Re-run CI3 run 35560002059 in aztec-packages — the ETARGET that killed it no longer reproduces. Once install.aztec.network/5.3.0-nightly.20260921/install returns 200, yarn build && yarn test can be run on this branch and the draft promoted.

🤖 Generated with Claude Code

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Created by claudebox · group: aztec-kit-nightly · Slack thread