feat: Reorg updates validator state

[hudem1]

No description provided.

[Copilot]

Pull request overview

This PR ensures validator state tracking in StateReconstructor is properly updated during chain reorgs, so MemDb-pinned reconstructed state is released when it becomes invalid after a reorg.

Changes:

• Add StateReconstructor.ReorgTo(BlockHeader) and trim prepared/pinned state beyond the reorg target.
• Switch prepared-queue entries from Hash256 state roots to BlockHeader so trimming can be based on block numbers.
• Extend tests to cover reorg interactions with _validHeader, _validHeaderCandidate, and MemDb pinning behavior.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
src/Nethermind.Arbitrum/Execution/Stateless/StateReconstructor.cs	Adds ReorgTo + prepared-queue trimming; changes prepared-queue element type to BlockHeader.
src/Nethermind.Arbitrum/Execution/ArbitrumExecutionEngine.cs	Updates PrepareForRecord to pass headers (not roots) into PreparedAddTrim.
src/Nethermind.Arbitrum/Execution/ArbitrumBlockFactory.cs	Calls stateReconstructor.ReorgTo(...) on reorg when validation is enabled.
src/Nethermind.Arbitrum.Test/Execution/Stateless/StateReconstructorTests.cs	Exposes/primes a reusable pruning simulation helper for new reorg tests.
src/Nethermind.Arbitrum.Test/Execution/Stateless/MarkValidTests.cs	Adds reorg-focused tests verifying validator state is cleared/preserved appropriately and MemDb pins are released.

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[codecov]

Codecov Report

❌ Patch coverage is 70.43478% with 34 lines in your changes missing coverage. Please review.
✅ Project coverage is 76.52%. Comparing base (83a3d65) to head (12b9a72).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...Arbitrum/Execution/Stateless/StateReconstructor.cs	68.80%	21 Missing and 13 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #826      +/-   ##
==========================================
+ Coverage   76.39%   76.52%   +0.13%     
==========================================
  Files         227      227              
  Lines       14151    14188      +37     
  Branches     2107     2119      +12     
==========================================
+ Hits        10810    10857      +47     
+ Misses       2584     2572      -12     
- Partials      757      759       +2     

Files with missing lines	Coverage Δ
...hermind.Arbitrum/Execution/ArbitrumBlockFactory.cs	40.84% <100.00%> (+1.27%)	⬆️
...mind.Arbitrum/Execution/ArbitrumExecutionEngine.cs	50.00% <100.00%> (ø)
...Arbitrum/Execution/Stateless/StateReconstructor.cs	60.83% <68.80%> (+3.73%)	⬆️

... and 1 file with indirect coverage changes

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