feat(spec-specs,tooling): run EELS under hive consume engine for all post-merge forks

[spencer-tb]

Description

EELS side of running the spec as a client under hive's consume engine
and consume enginex, for every post-merge fork (Paris through
Amsterdam, including the BPO forks and fork transitions).

Three layers:

• src/ethereum/forks/<fork>/execution_engine/ for every post-merge
  fork: the Engine API as readable spec, structured like the
  execution-apis documents and geth's catalyst API. Versioned
  structures (ExecutionPayloadV1…V4, PayloadAttributesV1…V4,
  BlobsBundleV1/V2, GetPayloadResponseV2…V6,
  PayloadStatusV1) are additive from Paris; versioned methods
  (new_payload_v1…v5, forkchoice_updated_v1…v4,
  get_payload_v1…v6) are thin wrappers carrying each version's
  rules — superseded versions answer UnsupportedForkError, the
  requests and block-access-list structural rules raise
  InvalidEngineParamsError — over shared cores that return
  PayloadStatusV1. A new payload validates on the branch of its
  parent without moving the canonical head; only a forkchoice update
  adopts a head, and the engine remembers every validated block with
  the state it produced, so nothing is re-executed. Payload building
  is specified by signature and response type but not implemented.
  Verified directly: 2,883 release fixtures across all forks and
  transitions through the versioned methods, including the expected
  unsupported-fork and invalid-params exceptions.
• src/ethereum_spec_tools/engine_server/: ethereum-spec-engine, a
  JSON-RPC server wrapping the spec. A ForkSpec registry maps each
  fork to its wire family (engine_newPayloadV1…V5,
  forkchoiceUpdatedV1…V4, payload field sets); the fork schedule
  comes from the hive HIVE_<FORK>_TIMESTAMP variables and payloads
  resolve their fork by timestamp (-38005 on version mismatch).
  Amsterdam executes via execute_block diffs; earlier forks via
  state_transition with reorg-by-replay from a genesis snapshot
  (state_mpt.copy_state). Structural param violations map to the
  Engine API error codes, including the requests-list rules and the
  empty-blockAccessList leniency the transition fixtures encode.
• Spec fixes surfaced by running the full fixture matrix:
  • calculate_excess_blob_gas reset blob accounting whenever the
    parent header was the previous fork's type; Prague through
    Amsterdam now accept the previous fork's header (PreviousHeader
    union), carrying excess across fork boundaries as mainnet did at
    Prague and as the fixtures expect. Pre-blob parents still reset.
  • bpo3/bpo4/bpo5 blob schedules were stale BPO2 placeholders,
    disagreeing with the framework schedule in this repo
    (execution_testing.forks); constants aligned (BPO3 21/32,
    update fractions 20609697 / 13739630).

Verified against the glamsterdam-devnet@v8.1.0 release: all 79,564
collectable engine tests and all 79,564 enginex tests — every fork and
all nine transition forks — pass through the exact consume simulator
sequences (real EngineRPC/EthRPC clients, JWT, rewind probe,
per-test reorgs): 159,128 executions, zero failures. In real hive:
consume-engine 136/136, consume-enginex 1030/1030, and a multi-fork
Cancun/Prague/transition smoke (2,462 tests, zero failures), plus ~49k
further clean executions across interrupted full runs.

Follow-up (hive repo): ethereum/hive#1596 adds the clients/eels
definition; ethpandaops/hive-tests#78 wires it into the devnet-8
workflows with the same limits as every other client.

Related Issues or PRs

N/A.

Checklist

• Ran fast static checks to avoid CI fails, see Code Standards & Verifying Changes: just static
• PR title has the form <type>(<area>): <title>, where <type> and <area> come from an appropriate C-<type>, respectively A-<area>, label. The title should match the target squash commit message.

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[codecov]

Codecov Report

❌ Patch coverage is 0.10428% with 958 lines in your changes missing coverage. Please review.
✅ Project coverage is 91.18%. Comparing base (a2936ed) to head (89904ef).

Files with missing lines	Patch %	Lines
...ereum/forks/amsterdam/execution_engine/requests.py	0.00%	113 Missing ⚠️
...hereum/forks/osaka/execution_engine/new_payload.py	0.00%	46 Missing ⚠️
...ereum/forks/prague/execution_engine/new_payload.py	0.00%	46 Missing ⚠️
...um/forks/amsterdam/execution_engine/new_payload.py	0.00%	44 Missing ⚠️
...ethereum/forks/amsterdam/execution_engine/types.py	0.00%	44 Missing ⚠️
...ereum/forks/cancun/execution_engine/new_payload.py	0.00%	44 Missing ⚠️
...rc/ethereum/forks/cancun/execution_engine/types.py	0.00%	44 Missing ⚠️
src/ethereum/forks/osaka/execution_engine/types.py	0.00%	44 Missing ⚠️
...rc/ethereum/forks/prague/execution_engine/types.py	0.00%	44 Missing ⚠️
src/ethereum/forks/paris/execution_engine/types.py	0.00%	40 Missing ⚠️
... and 28 more

Additional details and impacted files

@@                 Coverage Diff                 @@
##           forks/amsterdam    #3363      +/-   ##
===================================================
- Coverage            93.53%   91.18%   -2.36%     
===================================================
  Files                  624      661      +37     
  Lines                37074    38033     +959     
  Branches              3394     3480      +86     
===================================================
+ Hits                 34679    34680       +1     
- Misses                1645     2603     +958     
  Partials               750      750              

Flag	Coverage Δ
unittests	91.18% <0.10%> (-2.36%)	⬇️

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