[Ramses][AMR][RefinementHandler] Enforce 2:1 rule

[Akos299]

@tdavidcl @bcommerc , I added the linear interpolation to fill children cells.
Doing this, I reused the cells graph. compute slope limiter for conservatives variables,
interpolate parent cell fields and renormalize to ensure conservation.
I would like to have your feedback about this.

[gemini-code-assist]

Summary of Changes

Hello @Akos299, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request introduces a critical enhancement to the Adaptive Mesh Refinement (AMR) system by implementing and enforcing the 2:1 refinement rule. This rule is vital for maintaining the structural integrity and computational efficiency of adaptive grids by preventing large jumps in resolution between neighboring blocks. The changes involve adding new data structures to track block refinement levels and a parallel kernel to apply the rule, alongside significant documentation updates to improve code clarity.

Highlights

• 2:1 Refinement Rule Enforcement: The core change implements the 2:1 refinement rule within the AMR (Adaptive Mesh Refinement) system. This ensures that the refinement level of adjacent blocks does not differ by more than one, maintaining grid consistency.
• Block Level Storage: A new block_levels field has been added to SolverStorage.hpp to explicitly store and manage the refinement level of each block, which is crucial for enforcing the 2:1 rule.
• Documentation Improvements: Extensive Doxygen-style comments and inline clarifications have been added across multiple files, enhancing the understanding of AMR graph construction, neighborhood finding, and various functions related to the AMR process.

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[gemini-code-assist]

Code Review

This pull request introduces a new block_levels field to SolverStorage and implements a SYCL kernel in AMRGridRefinementHandler to enforce the 2:1 refinement restriction using block neighbor graphs and block levels. It also adds extensive Doxygen comments to clarify the purpose of graph building nodes (FindBlockNeigh, BlockNeighToCellNeigh) and AMR-related functions. Review comments address a critical race condition in the new SYCL kernel, recommending the use of sycl::atomic_ref for atomic updates, and suggest removing commented-out code, clarifying ambiguous comments, correcting typos in documentation, and refactoring repetitive code blocks for better maintainability.

[github-actions]

Workflow report

workflow report corresponding to commit 939a6a7
Commiter email is leodasce.sewanou@ens-lyon.fr

Pre-commit check report

Pre-commit check: ✅

trim trailing whitespace.................................................Passed
fix end of files.........................................................Passed
check for merge conflicts................................................Passed
check that executables have shebangs.....................................Passed
check that scripts with shebangs are executable..........................Passed
check for added large files..............................................Passed
check for case conflicts.................................................Passed
check for broken symlinks................................................Passed
check yaml...............................................................Passed
detect private key.......................................................Passed
No-tabs checker..........................................................Passed
Tabs remover.............................................................Passed
Validate GitHub Workflows................................................Passed
clang-format.............................................................Passed
black....................................................................Passed
ruff check...............................................................Passed
Check doxygen headers....................................................Passed
Check license headers....................................................Passed
Check #pragma once.......................................................Passed
Check SYCL #include......................................................Passed
No ssh in git submodules remote..........................................Passed

Test pipeline can run.