feat: v0.2.0 — sequence helpers, irregular-time stepping, Bayesian filtering, MLE fit

[bionicbutterfly13]

Summary

Expands linoss-dynamics from a single-step physics primitive into a higher-level multi-use library for oscillatory state-space dynamics, while keeping the core NumPy-only.

This is the first PyPI release. v0.1.0 was never published.

What changed

Core (NumPy-only)

• linoss_scan(U, A, dt, ...) — sequence helper running linoss_step over a (T, n) input.
• damped_oscillator_closed_form — analytic step supporting variable dt (irregular sampling); handles underdamped, critically damped, and overdamped regimes via exact matrix exponential.
• stability module: is_stable, eigvals_to_freq_damping, freq_damping_to_oscillator_block, period_from_omega, harmonic_stack.
• filters module: kalman_filter, rts_smoother — Bayesian state estimation over oscillator state-space models.

Optional [probabilistic] extra (scipy)

• discretize_lti_with_noise, discretize_control, oscillator_mats — van Loan exact matrix-exponential discretization.
• fit_oscillator_mle — MLE parameter recovery via L-BFGS-B in log-parameter space.

Docs and tutorials

• examples/ directory with 8 runnable tutorials.
• docs/api.md — per-function API reference.
• docs/roadmap.md — public vision document (v0.3 candidates, v1.0 unified oscillator+attractor goal, v1.x spatial extensions, explicit non-goals).
• README Vision section linking to roadmap.
• PROVENANCE.md: framing-only attribution (no shared code with upstream JAX impl).
• architecture.md: lineage section grounding the package in the research family.

Notable

• scipy-gated symbols use module-level __getattr__ to raise LinOSSError with install hint if scipy is absent (instead of bare AttributeError).
• Empty-array guards added to is_stable for both modes.
• Core remains NumPy-only; SciPy is gated behind [probabilistic].

Test plan

• 119/119 pytest pass on Python 3.11
• CI matrix green on 3.10, 3.11, 3.12 (this PR)
• python -m ruff check src tests examples clean
• python -m compileall -q src tests examples clean
• python -m build produces wheel + sdist
• python -m twine check dist/* PASSED for both
• Clean-venv install from local wheel: all 23 public symbols importable, smoke test green
• Independent Reviewer review: PASS WITH FINDINGS — all 3 Highs fixed before commit

Roadmap

This release is the v0.2.0 milestone of the public roadmap at docs/roadmap.md. v1.0 will introduce unified oscillator + attractor primitives. v1.x explores spatio-temporal extensions (BioOSS-class). See roadmap for the full vision.