)

* fix(bal): align EIP-7928 BlockAccessIndex with uint32 spec, add validation

Widens BlockAccessIndex from uint16 to uint32 per EIP-7928 (commit 645099785a)
and geth bal-devnet-4. Hardens the BAL decoder so truncated/malformed wire
bytes produce a clean RlpException at engine_newPayloadV5 instead of crashing.
Adds the missing validation rules geth bal-devnet-4 enforces: empty
storage_changes per slot is rejected, and BlockAccessIndex is bounded by
[0, txCount + 1].

Decoder primitives:
- New Rlp.ValueDecoderContext.DecodeUInt() / RlpStream.Encode(uint) /
  Rlp.LengthOf(uint) helpers.
- Rlp.Decode<T> and Rlp.DecodeArrayPool<T> wrap IndexOutOfRangeException /
  ArgumentOutOfRangeException as RlpException so any truncated-RLP primitive
  read surfaces consistently.
- BlockAccessListDecoder rejects an empty AccountChanges entry (0xc0 inside
  the outer list) and SlotChangesDecoder rejects an empty StorageChange list
  for a slot — geth bal-devnet-4 "empty storage writes" parity.

Type widening:
- IIndexedChange.Index, BalanceChange/NonceChange/CodeChange/StorageChange.Index,
  BlockAccessList.Index and BlockAccessIndex on the Change journal record all
  become uint. SortedList<int, T> keys flip to SortedList<uint, T>; ushort
  query parameters on AccountChanges become uint.

Prestate sentinel preservation:
- Replaces the legacy -1 int sentinel with Eip7928Constants.PrestateIndex
  (uint.MaxValue). Adds PrestateAwareIndexComparer that orders the sentinel
  before all real indices, restoring the iteration semantics that
  AccountChanges.GetBalance/GetNonce/GetCode/AccountExists and
  ApplyStateChanges' [^1].Index check rely on.
- Decoder-built SortedLists also use the prestate-aware comparer so that
  LoadPreStateToSuggestedBlockAccessList grafting prestate onto the suggested
  BAL after decode keeps it sorted first.
- Loop predicates that compare change.Key directly against blockAccessIndex
  explicitly skip PrestateIndex so the raw uint comparison doesn't trigger
  on the huge sentinel value.

Validation:
- BlockValidator gains ValidateBlockLevelAccessListIndexBounds enforcing
  index <= txCount + 1 (mirrors geth's index < txCount + 2 check) with a new
  BlockLevelAccessListIndexOutOfRange error message.

Tests:
- New PrestateAwareIndexComparerTests, AccountChangesPrestateTests covering
  the comparer and prestate-fallback iteration semantics.
- BlockAccessListDecoderTests adds: empty-bytes / truncated-outer-list /
  inner-empty-list throw RlpException; empty storage_changes per slot throw;
  decoded SlotChanges accepts a later prestate graft as first; BalanceChange
  round-trips for indices 0x10_0000 and uint.MaxValue.
- BlockValidatorTests adds tx-index bound cases (0, 1 valid; 2,
  uint.MaxValue rejected for a 0-tx block).
- ExecutionPayloadV4Tests covers the engine-API decoding-error path for
  malformed BAL bytes.

* style: drop unused usings flagged by IDE0005

CI surfaced four IDE0005 warnings (treated as errors):
- BlockAccessListManager: drop `using Nethermind.Crypto;` —
  Keccak.OfAnEmptySequenceRlp comes from Nethermind.Core.Crypto, already imported.
- PrestateAwareIndexComparerTests / AccountChangesPrestateTests: drop
  `using Nethermind.Core;` — Eip7928Constants resolves via the test's parent
  namespace Nethermind.Core.Test.BlockAccessLists.
- Eip8037Tests: drop `using System;` — no System.* type referenced directly.

* fix(bal): record system pre/post-block SSTOREs as reads per EIP-7928 v5.7.0

EIP-7928 v5.7.0 specifies that SSTOREs performed during system pre-block calls
(EIP-2935 BlockHashHistory, EIP-4788 BeaconRootContract) and post-block calls
(EIP-7002 withdrawal requests, EIP-7251 consolidation requests) are recorded
in the BAL as storage reads on the touched slot — not as storage changes with
post-values. Same-value writes are skipped entirely. Without this, nethermind
generated a BAL whose Keccak256 differs from what eels-built fixtures expect,
so the BlockAccessListHash check fails for every Amsterdam block that touches
a system contract slot (most pyspec tests).

IWorldState gains an opt-in scope:

  IDisposable? BeginSystemPreBlockScope()

TracedAccessWorldState implements it via an int depth counter. While depth > 0,
Set(storageCell, value) reclassifies the recording: AddStorageRead when the
slot value would change, no-op when unchanged. The state mutation still
applies via the inner world state.

BlockAccessListManager wraps the three system contract entry points with the
scope: StoreBeaconRoot (EIP-4788 system tx), ApplyBlockhashStateChanges
(EIP-2935 fast-path Set), and ProcessExecutionRequests (EIP-7002 / EIP-7251
post-block system txs).

Parallel-mode state application:

In parallel processing, non-system slots wrap stateProvider with
BlockAccessListBasedWorldState whose Set is a no-op — actual state mutation
relies on ApplyStateChanges replaying the suggested BAL's storage_changes.
With the spec-correct BAL containing reads instead of changes for the system
slots, ApplyStateChanges has nothing to replay for them, so the canonical
state would diverge.

TxProcessorWithWorldState gains an `isSystemSlot` parameter. The
ParallelTxProcessorWithWorldStateManager passes `isSystemSlot: i == 0 || i ==
_len - 1` (pre-execution and post-execution slots). For those slots, the
TracedAccessWorldState wraps stateProvider directly, so system pre/post-block
SSTOREs mutate the canonical state regardless of BAL recording. Tx slots
(1..n) keep the BAL-backed wrapping unchanged.

Sequential pyspec tests (which is what the Ethereum.Blockchain.Pyspec.Test
suite runs) are unaffected by the parallel slot change but benefit from the
BAL recording fix; the BlockAccessListHash check now passes for blocks that
previously failed solely on system pre-block storage encoding.

Note: a residual InvalidStateRoot mismatch remains on a subset of Amsterdam
pyspec tests (~70/360 ecrecover_weird_v + a similar slice of stMemoryStress).
These were previously masked by the BAL hash error firing first. The
remaining state divergence appears unrelated to BAL recording and is left
for follow-up.

* test(jsonrpc): update Eth_get_block_access_list_by_* fixtures for EIP-7928 v5.7.0

The Eth_get_block_access_list_by_hash and _by_number tests had hardcoded the
pre-v5.7.0 shape, recording the EIP-2935 BlockHashHistory system pre-block
SSTORE as a storageChanges entry with the post-value. v5.7.0 records system
pre-block SSTOREs as storageReads (slot key only).

Updated both expected JSON strings to match the new spec-compliant output.

* Revert "fix(bal): record system pre/post-block SSTOREs as reads per EIP-7928 v5.7.0"

This reverts commit 364f294.

* Revert "test(jsonrpc): update Eth_get_block_access_list_by_* fixtures for EIP-7928 v5.7.0"

This reverts commit 937ca5d.

* review: address PR #11362 feedback

- Rlp.DecodeArrayPool<T>: dispose partially-allocated ArrayPoolList<T>
  before wrapping IndexOutOfRangeException/ArgumentOutOfRangeException
  as RlpException so the rented buffer is returned to the pool.
- Rlp.ValueDecoderContext.DecodeUInt(): collapse case 0 to a single
  `return RlpHelpers.ThrowNonCanonicalInteger(Position)` (DoesNotReturn,
  uint) to match DecodeInt and drop the dead `return default`.
- BlockAccessListManager.GetPostExecution(): use uint.MaxValue literal
  to match the uint? balIndex parameter.
- AccountChanges.SlotChangesAtIndex: build the returned SortedList with
  PrestateAwareIndexComparer.Instance so a later prestate graft sorts
  first, matching the rest of the codebase.
- PrestateAwareIndexComparer xmldoc: clarify that decoded BALs also use
  this comparer (so later prestate grafting preserves order).

* test(pyspec): skip EELS bal@v5.7.0 ported_static fixtures with legacy state-test conversion bug

EELS's `from_state_test` conversion for ported_static tests omits the
EIP-2935 / EIP-4788 system pre-block SSTORE entries from the suggested
BAL, while a real client (and Nethermind) executes them — so every such
fixture's BlockAccessListHash diverges from what we compute. 91 such
tests were the entire residual pyspec failure set on the bal-devnet-4a
branch.

Detect the conversion via the legacy difficulty value 0x20000 baked
into the post-merge mixHash field — real prevRandao would never be
exactly 0x...020000 — and Assert.Ignore those tests.

Track upstream EELS fix; remove the guard once bal@>v5.7.0 ships with
the system pre-block SSTOREs included in the BAL.

* fix(pyspec test): drop ?-annotation in non-nullable file

CS8632: PyspecTestFixture.cs is not under `#nullable enable`, so the
`string?` introduced in 6fb6527 broke the build of every pyspec
job. `string` works the same here — the value already gets a null
check on the next line.

* test(pyspec): also skip blockchain_test_engine_from_state_test variant

The first guard only walked test.Blocks, which is null for engine
fixtures. Engine fixtures keep the same legacy 0x...020000 sentinel,
just on the JSON `prevRandao` field of the engine_newPayload params.
Walk EngineNewPayloads too.

* Update tests

* fix(eip-8037): pin cost_per_state_byte at static 1174 for bal-devnet-4

bal-devnet-4 keeps cost_per_state_byte static at 1174 (carried over from
bal-devnet-3), removing the per-block-gas-limit scaling formula that an
earlier draft of EIP-8037 specified. snøbal-devnet-4 fixtures encode the
same gas usage (63574) at 1M / 5M / 10M / 30M block gas limits, confirming
the value is now invariant across blockGasLimit.

Reduce CalculateCostPerStateByte to a direct return of CostPerStateByte
and drop the dynamic-quantization helpers and BitOperations dependency.
The blockGasLimit parameter is retained on call sites in case a future
devnet revisits per-block scaling. Update the EIP-8037 unit test to pin
the static behaviour rather than asserting quantized values.

- Replace SortedDictionary with Dictionary in BlockAccessList for O(1)
  account lookups on the EVM hot path (was O(log n) with 20-byte span
  comparisons). Sorted enumeration preserved for encoding/validation.
- Merge TryGetDelegation + GetCachedCodeInfo into a single call in
  InstructionCall, eliminating a redundant GetCodeHash per CALL opcode.
- Inline IsDeadAccount in EXTCODEHASH to avoid a second GetCodeHash
  call for the same address.

commit 3a3078f
Author: Marc Harvey-Hill <10379486+Marchhill@users.noreply.github.com>
Date:   Tue Apr 28 18:23:03 2026 +0200

    delete old tests

commit 95de888
Merge: 244c2c6 31a673a
Author: MarekM25 <marekm2504@gmail.com>
Date:   Tue Apr 28 18:08:12 2026 +0200

    Merge branch 'master' into engine-api-glamsterdam-cleanup

commit 244c2c6
Author: MarekM25 <marekm2504@gmail.com>
Date:   Tue Apr 28 18:05:32 2026 +0200

    fix lint

commit 9194b8f
Author: MarekM25 <marekm2504@gmail.com>
Date:   Tue Apr 28 18:04:19 2026 +0200

    remove tests

commit eedfbb7
Author: MarekM25 <marekm2504@gmail.com>
Date:   Tue Apr 28 17:57:46 2026 +0200

    revert formatting changes and zero hash stuff

commit dc71aa5
Author: MarekM25 <marekm2504@gmail.com>
Date:   Tue Apr 28 17:38:42 2026 +0200

    cleanups

commit ec2fce3
Author: MarekM25 <marekm2504@gmail.com>
Date:   Tue Apr 28 17:33:11 2026 +0200

    fixing

commit 90a1da8
Author: MarekM25 <marekm2504@gmail.com>
Date:   Tue Apr 28 17:15:58 2026 +0200

    remove test

commit 4451656
Author: MarekM25 <marekm2504@gmail.com>
Date:   Tue Apr 28 17:12:32 2026 +0200

    Cleanup mess

commit 2425748
Merge: 4a90460 a36154c
Author: Stavros Vlachakis <89769224+svlachakis@users.noreply.github.com>
Date:   Mon Apr 27 14:33:36 2026 +0300

    Merge branch 'master' into engine-api-glamsterdam

commit 4a90460
Merge: 3549768 18d60a4
Author: Stavros Vlachakis <89769224+svlachakis@users.noreply.github.com>
Date:   Mon Apr 27 14:08:25 2026 +0300

    Merge branch 'master' into engine-api-glamsterdam

commit 3549768
Merge: 30fcc36 b71c352
Author: Stavros Vlachakis <89769224+svlachakis@users.noreply.github.com>
Date:   Mon Apr 27 14:07:39 2026 +0300

    Merge branch 'master' into engine-api-glamsterdam

commit 30fcc36
Merge: 540e4a2 ed6a354
Author: Stavros Vlachakis <89769224+svlachakis@users.noreply.github.com>
Date:   Mon Apr 27 13:09:48 2026 +0300

    Merge branch 'master' into engine-api-glamsterdam

commit 540e4a2
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Sun Apr 26 04:52:49 2026 +0300

    minor fixes

commit 010547b
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Sun Apr 26 03:22:39 2026 +0300

    test fixes

commit 6fcc136
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Sun Apr 26 02:11:12 2026 +0300

    fixes

commit 0bccb06
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Sun Apr 26 01:52:02 2026 +0300

    test fix

commit 830c578
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Sun Apr 26 01:38:55 2026 +0300

    fix tests

commit 1f5fd2c
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Sun Apr 26 01:35:17 2026 +0300

    claude review again

commit d87491f
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Sun Apr 26 00:57:57 2026 +0300

    fixes

commit dd431e2
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Sun Apr 26 00:51:52 2026 +0300

    fix tests

commit 71dc99f
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Sat Apr 25 22:40:50 2026 +0300

    fixes

commit 9c03d12
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Sat Apr 25 22:32:58 2026 +0300

    update per 786

commit a4c4f3c
Merge: fc49e7e 9cba44c
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Sat Apr 25 21:38:25 2026 +0300

    Merge remote-tracking branch 'origin/master' into engine-api-glamsterdam

commit fc49e7e
Merge: bca0c63 42c551f
Author: Stavros Vlachakis <89769224+svlachakis@users.noreply.github.com>
Date:   Mon Apr 20 16:14:33 2026 +0300

    Merge branch 'master' into engine-api-glamsterdam

commit bca0c63
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Mon Apr 20 16:14:10 2026 +0300

    remove unused import

commit 3d2c973
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Mon Apr 20 16:09:17 2026 +0300

    fix taiko tests

commit b30ef5c
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Mon Apr 20 15:34:35 2026 +0300

    fix tests

commit 6f131cd
Merge: a8c884a 0fe41f4
Author: Stavros Vlachakis <89769224+svlachakis@users.noreply.github.com>
Date:   Mon Apr 20 14:55:46 2026 +0300

    Merge branch 'master' into engine-api-glamsterdam

commit a8c884a
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Mon Apr 20 14:54:40 2026 +0300

    conflicts fix

commit 96eb912
Merge: 82a1f70 425a2a3
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Mon Apr 20 14:52:33 2026 +0300

    Merge remote-tracking branch 'origin/master' into engine-api-glamsterdam

    # Conflicts:
    #	src/Nethermind/Nethermind.Merge.Plugin/BlockTreeExtensions.cs
    #	src/Nethermind/Nethermind.Merge.Plugin/Handlers/ForkchoiceUpdatedHandler.cs
    #	src/Nethermind/Nethermind.Taiko/Rpc/TaikoForkchoiceUpdatedHandler.cs

commit 82a1f70
Merge: 7b6133f 436c65b
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Mon Apr 20 13:16:55 2026 +0300

    Merge remote-tracking branch 'origin/master' into engine-api-glamsterdam

commit 7b6133f
Merge: 2f068ec 02c2026
Author: Stavros Vlachakis <89769224+svlachakis@users.noreply.github.com>
Date:   Thu Apr 16 14:49:46 2026 +0300

    Merge branch 'master' into engine-api-glamsterdam

commit 2f068ec
Merge: bdd7ee5 5464c8b
Author: Stavros Vlachakis <89769224+svlachakis@users.noreply.github.com>
Date:   Thu Apr 16 14:10:02 2026 +0300

    Merge branch 'master' into engine-api-glamsterdam

commit bdd7ee5
Merge: f09cb41 bfaaeb0
Author: Stavros Vlachakis <89769224+svlachakis@users.noreply.github.com>
Date:   Wed Apr 15 16:45:19 2026 +0300

    Merge branch 'master' into engine-api-glamsterdam

commit f09cb41
Merge: 370acdf cf03d18
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Wed Apr 15 16:24:17 2026 +0300

    Merge remote-tracking branch 'origin/master' into engine-api-glamsterdam

commit 370acdf
Merge: d1d0370 6cd0ea4
Author: Stavros Vlachakis <89769224+svlachakis@users.noreply.github.com>
Date:   Mon Apr 13 14:28:21 2026 +0300

    Merge branch 'master' into engine-api-glamsterdam

commit d1d0370
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Fri Apr 10 17:30:54 2026 +0300

    more fixes

commit c99d6cc
Merge: 4d0f215 a52cb90
Author: Stavros Vlachakis <89769224+svlachakis@users.noreply.github.com>
Date:   Fri Apr 10 17:24:06 2026 +0300

    Merge branch 'master' into engine-api-glamsterdam

commit 4d0f215
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Fri Apr 10 17:23:42 2026 +0300

    claude review

commit cb6defe
Merge: af63142 0057bd8
Author: Stavros Vlachakis <89769224+svlachakis@users.noreply.github.com>
Date:   Fri Apr 10 12:34:37 2026 +0300

    Merge branch 'master' into engine-api-glamsterdam

commit af63142
Merge: 1b338f3 2f24891
Author: Stavros Vlachakis <89769224+svlachakis@users.noreply.github.com>
Date:   Fri Apr 10 12:08:36 2026 +0300

    Merge branch 'master' into engine-api-glamsterdam

commit 1b338f3
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Fri Apr 10 12:08:13 2026 +0300

    claude review

commit 619259b
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Thu Apr 9 18:32:59 2026 +0300

    taiko fix

commit d067793
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Thu Apr 9 18:19:14 2026 +0300

    cleaner design

commit 1e27be1
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Thu Apr 9 18:12:04 2026 +0300

    improve tests matching the specs

commit a77e182
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Thu Apr 9 18:04:58 2026 +0300

    improve test

commit 4ba069c
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Thu Apr 9 18:01:59 2026 +0300

    fix comment

commit fe6f9b0
Author: stavrosvl7 <stavrosvl7@gmail.com>
Date:   Thu Apr 9 17:53:57 2026 +0300

    engine api changes as per ethereum/execution-apis#770
                              ethereum/execution-apis#760

…halt

Top-level REVERT preserves gas_left, so the spilled portion of state_gas_used
(originally drawn from gas_left) is still in the user's pocket and must be
refunded to the reservoir alongside the reservoir-funded portion. Top-level
halt burns gas_left, so the spilled portion was paid out of gas the user can
no longer reclaim — only the reservoir-funded portion is restorable.

Splits RefundRevertedTopLevelStateGas into a revert path (full refund) and a
new RefundHaltedTopLevelStateGas (reservoir-only, spill discarded) and wires
the halt error sites to the latter.

… GetContentLength

The pyspec fixture archive ships three uncovered directories: a stray state-
tests transition fork, plus two test types we never wired in. Adds:

- CancunToPragueAtTime15kStateTests — fills a one-class gap in Tests.cs
- PyspecSyncBlockchainTestFixture + AmsterdamSyncBlockchainTests,
  OsakaSyncBlockchainTests — runs blockchain_tests_sync fixtures through the
  engine harness; the additional syncPayload field is left for a follow-up
- TestType.Transaction + TransactionTest/Json/Base + ConvertTransactionTests
  + PyspecTransactionTestFixture — decodes raw txbytes via Rlp.Decode and
  matches expected EEST exception tokens (TYPE_4_*) against the validator's
  ValidationResult.Error or RLP decode message; covers AmsterdamTxTests,
  OsakaTxTests, PragueTxTests fork directories

Bumps FlatDB pyspec chunking from 4 to 16 to match the regular workflow —
~860 tests/shard instead of ~3,437/shard, well under the 256/matrix cap and
the 20-minute job timeout.

…es with master

Three behavior-preserving reductions to BlockAccessListBasedWorldState's
diff vs master, keeping (a) the ref-readonly UInt256/ValueHash256 interface
returns and (b) the TracedAccessWorldState SLOAD allocation savings:

(2) Restore _codeChangesByHash + BuildCodeChangesByHash + TryGetDeclaredCode
    + functional GetCode(in ValueHash256). GetCode-by-hash is no longer a
    null stub.

(3) Re-merge Get/GetOriginal to master's twin-body shape using
    _readScratch/_originalScratch EvmWord fields. Master's pattern is
    already zero-allocation here (MemoryMarshal.CreateReadOnlySpan +
    WithoutLeadingZeros, no .ToArray()), so dropping the unified
    GetAtCurrentIndex helper loses no perf — the byte[32] reuse only
    saved an allocation in TracedAccessWorldState.GetInternal, which is
    untouched.

(4) Re-collapse ResolveAccountChanges + GetParentReader callers back to
    ResolveContext tuple. Master's pattern.

ReadOnlySlotChanges: the TryGetLastBefore(uint, Span<byte>, out span)
buffer overload's only consumer was BlockAccessListBasedWorldState.Get/
GetOriginal; reverted to master's TryGetLastBefore(uint, out StorageChange)
signature. The Get(uint, buffer) wrapper goes away too.

Kept on the branch:
  * ref readonly UInt256 GetBalance / ref readonly ValueHash256 GetCodeHash
    on IWorldState (with _scratchBalance/_scratchCodeHash fields).
  * _scratchStorage byte[32] in TracedAccessWorldState.GetInternal.
  * ReadOnlyBlockAccessList / ReadOnlyAccountChanges / ReadOnlySlotChanges
    type substitutions.

Diff vs master in BlockAccessListBasedWorldState: 237 -> 66 lines (~72%
reduction). All 18 BlockAccessListBasedWorldStateTests pass, 51 BAL
Core.Test pass, 66/66 Bpo2ToAmsterdam pyspec tests pass.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

M1: ReadOnlySlotChanges.Equals used Changes.SequenceEqual(...) with
    using System.Linq in scope. Since Changes is StorageChange[], that
    bound to Enumerable.SequenceEqual<T> (allocates an iterator) rather
    than MemoryExtensions.SequenceEqual<T> on ReadOnlySpan<T>. Same
    pattern that was fixed in ReadOnlyAccountChanges.Equals (M1 round 1);
    missed it on the slot-changes file. Force the span overload via
    (ReadOnlySpan<StorageChange>)Changes and drop the now-unused
    System.Linq import.

L1: Drop the "// Otherwise, push the account's code hash." noise
    comment from InstructionExtCodeHash — it restates the next line.
    Came back when EXTCODEHASH was reverted to master's body; cleaner
    to remove on both sides per coding-style.md ("Comments that merely
    restate the code are noise — don't add them, and remove them when
    you encounter them"). The comment above it stays — that one earns
    its place via the EIP-1052 spec reference.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

…ary/HashSet

GeneratedBlockAccessList and GeneratedAccountChanges keep per-account and per-slot
collections sorted only because the RLP encoder needs sorted output (EIP-7928).
Building the sort incrementally costs O(log n) on every per-tx Merge across three
collections; switching to Dictionary/HashSet defers ordering to a one-shot sort at
the encoder boundary.

Adds GetSortedAccountChanges/GetSortedStorageChanges/GetSortedStorageReads for the
encoder, switches the BlockAccessListDecoder/AccountChangesDecoder encode paths to
them, and refactors SlotChangesAtIndexEqual from a lockstep merge over two sorted
streams to a generated-side walk + binary search into the sorted suggested side.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

…mark

- GeneratedSlotChanges/GeneratedAccountChanges implement IComparable<T> so
  sort sites use GenericComparer.GetOptimized<T>() (project pattern) instead
  of static Comparison<T> lambdas.
- ToString avoids ToArray() + string.Join allocation by walking the sorted
  span into the StringBuilder directly; constrained ToString skips boxing
  for value-type elements (UInt256).
- Add BlockAccessListBenchmarks under Nethermind.Benchmark covering per-tx
  Merge, EncodeToBytes, and end-to-end build+merge+encode.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

…gator