Implement SolverCore.reset!(solver) function

[MaxenceGollier]

closes #268

Added a function that resets the initial vector of the power norm iteration method.

[Copilot]

Pull request overview

This PR addresses issue #268 by eliminating solver statefulness across repeated solve! calls: it resets the initial vector used by the power-method-based operator-norm estimate so running the same solver instance twice yields consistent results.

Changes:

• Added _reset_power_method! helper to reinitialize the power method starting vector.
• Invoked _reset_power_method! at the beginning of solve! for TRSolver and R2NSolver.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 5 comments.

File	Description
src/utils.jl	Adds _reset_power_method! used to reinitialize the power iteration vector.
src/TR_alg.jl	Calls _reset_power_method! at the start of solve! to prevent cross-run drift.
src/R2N.jl	Calls _reset_power_method! at the start of solve! to prevent cross-run drift.

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[codecov]

Codecov Report

❌ Patch coverage is 0% with 18 lines in your changes missing coverage. Please review.
✅ Project coverage is 83.73%. Comparing base (e0f214d) to head (3c898ec).
⚠️ Report is 268 commits behind head on master.

Files with missing lines	Patch %	Lines
src/R2N.jl	0.00%	5 Missing ⚠️
src/TR_alg.jl	0.00%	5 Missing ⚠️
src/R2DH.jl	0.00%	3 Missing ⚠️
src/TRDH_alg.jl	0.00%	3 Missing ⚠️
src/utils.jl	0.00%	2 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           master     #293       +/-   ##
===========================================
+ Coverage   61.53%   83.73%   +22.20%     
===========================================
  Files          11       13        +2     
  Lines        1292     1642      +350     
===========================================
+ Hits          795     1375      +580     
+ Misses        497      267      -230     

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[MaxenceGollier]

@MohamedLaghdafHABIBOULLAH, in JSOSolvers.jl, the way we actually do it is just to have a reset function available, not to directly call it at each solve. That's what i will do to keep the solvers compliant.

[MaxenceGollier]

Let me know what you think, @MohamedLaghdafHABIBOULLAH.