[v0.4.0] Stan Integration & Multi-Sampler Support

[kdh4win4]

Summary

Extend BioAnchor beyond PyMC to support Stan (CmdStanPy) and NumPyro/JAX-based MCMC workflows, making the tool sampler-agnostic.

Planned Features

• Stan / CmdStanPy support — extract diagnostics from Stan model fits
• Sampler-agnostic diagnostics — unified diagnostics extraction layer regardless of backend sampler (PyMC, Stan, NumPyro)
• NumPyro / JAX support — lightweight adapter for NumPyro models

Motivation

PyMC is one of several major MCMC frameworks. Supporting Stan and NumPyro significantly broadens BioAnchor's user base across the Bayesian research community.

Related

• Depends on: v0.1.0 (PyMC pipeline)
• See also: ROADMAP.md