Add prox_evals to solver_specific

[MohamedLaghdafHABIBOULLAH]

@dpo @MaxenceGollier
I’ve added the number of proximal evaluations. for R2N, LM, and TR, and I’m still waiting on LMTR.
Note that for R2, R2DH, and TRDH, using stats.iter alone is sufficient to capture the number of proximal evaluations.

[Copilot]

Pull Request Overview

This PR adds tracking of proximal evaluations to three solver algorithms by introducing a prox_evals counter. The counter tracks both initial proximal evaluations and additional evaluations from subsolvers during the optimization process.

• Adds prox_evals counter initialization and tracking to TR, R2N, and LM algorithms
• Increments counter at algorithm start and after each subsolver execution
• Stores the count in solver-specific statistics for monitoring

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
src/TR_alg.jl	Adds proximal evaluation tracking to Trust Region algorithm
src/R2N.jl	Adds proximal evaluation tracking to R2N algorithm
src/LM_alg.jl	Adds proximal evaluation tracking to Levenberg-Marquardt algorithm

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[MaxenceGollier]

All tests have been interrupted @MohamedLaghdafHABIBOULLAH can you try again please ?
Also, I suspect that allocation tests won't pass anymore on these because set_solver_specific! allocates if you don't add the entry already in src/utils.jl

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.15%. Comparing base (e0f214d) to head (18fe099).
⚠️ Report is 162 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff             @@
##           master     #222       +/-   ##
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+ Coverage   61.53%   86.15%   +24.62%     
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  Files          11       13        +2     
  Lines        1292     1575      +283     
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+ Hits          795     1357      +562     
+ Misses        497      218      -279     

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[MohamedLaghdafHABIBOULLAH]

Thanks.