Bayesian extend/resume

[rozyczko]

Support for resuming and extending Bayesian MCMC chains using the BUMPS DREAM sampler.
Added ability to save and reload sampler state and continue chains across sessions.

• Resume and extend MCMC chains:

  • Added resume_state parameter to mcmc_sample and sample methods in both fitter.py and minimizer_bumps.py, allowing users to continue sampling from a saved chain state. This includes documentation of the "ring-buffer contract" for extending chains without losing samples.

• Population/chains argument resolution:

  • Introduced _resolve_population_alias method to handle both chains and population arguments, raising an error if both are set with different values, improving API clarity and preventing silent bugs.

[codecov]

Codecov Report

❌ Patch coverage is 79.01235% with 17 lines in your changes missing coverage. Please review.
✅ Project coverage is 82.57%. Comparing base (aadbd48) to head (84ad75b).

Files with missing lines	Patch %	Lines
src/easyscience/fitting/multi_fitter.py	12.50%	14 Missing ⚠️
.../easyscience/fitting/minimizers/minimizer_bumps.py	95.08%	3 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #257      +/-   ##
===========================================
- Coverage    82.65%   82.57%   -0.09%     
===========================================
  Files           62       62              
  Lines         5023     5096      +73     
===========================================
+ Hits          4152     4208      +56     
- Misses         871      888      +17     

Flag	Coverage Δ
integration	44.19% <67.90%> (+0.31%)	⬆️
unittests	81.80% <62.96%> (-0.34%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
src/easyscience/fitting/fitter.py	97.29% <100.00%> (+0.01%)	⬆️
src/easyscience/fitting/minimizers/__init__.py	100.00% <100.00%> (ø)
.../easyscience/fitting/minimizers/minimizer_bumps.py	95.69% <95.08%> (-0.26%)	⬇️
src/easyscience/fitting/multi_fitter.py	82.14% <12.50%> (-16.41%)	⬇️