fix: bound getTxEffects oracle receipt reads

[AztecBot]

Summary

• Bound aztec_utl_getTxEffects receipt reads to 16 concurrent node requests instead of firing every unique hash at once.
• Added a PXE oracle unit test that proves a 17-hash batch only starts the first 16 reads until one completes.

Merge queue investigation

• aztec-packages#24638 was added to the merge queue at 2026-07-10 12:04 UTC and removed at 2026-07-10 12:30 UTC.
• The PR is currently mergeable/clean; I did not find a merge conflict.
• The failed required run was merge-group CI3 run https://github.com/AztecProtocol/aztec-packages/actions/runs/29091411736 on queue SHA d85a013b29f50ea96ac11f748faf413090722802.
• The failed job was ci, exiting with code 124. The GitHub log pointed to arm64 a1-fast running ./bootstrap.sh ci-fast, dashboard log http://ci.aztec-labs.com/c6ba3ae49a0d1da9, nested log http://ci.aztec-labs.com/1783685099951146, and test-engine log http://ci.aztec-labs.com/33d67695ed900e00.
• I did not find a test assertion failure in the dashboard logs; the failure was a timeout. The original feature PR aztec-packages#24636 has no failed current checks.

Verification

• git diff --check passed.
• ./bootstrap.sh ci does not exist as a root bootstrap target on this branch; it exits with Unknown command: ci.
• ./bootstrap.sh ci-fast was attempted locally because that is the failed merge-queue command, but this container has no Docker/Redis cache path and failed early in test_engine after only four early commands were written to /tmp/test_cmds; this is not the same failure as the remote timeout.
• Focused Yarn tests are currently blocked because the Noir JS portal packages are missing and noir/bootstrap.sh cannot fetch just@1.42.4 from crates.io in this container (dns error, Label contains invalid characters: Err(Errors)).

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Created by claudebox · group: slackbot