Enforce reproducibility & dashboard load in CI, add Python matrix and docs polish

[ethanbuckley]

Note

Drafted by an LLM-based AI tool (Claude Code/Fable 5).

What & why

Two verification steps that were previously only run by hand are now enforced in CI, plus a Python-version matrix and a small docs/typing polish. No change to model behaviour: data/results.json is byte-for-byte unchanged and seiqr.py is untouched.

Changes

• Reproducibility regression test (tests/test_reproducibility.py) — regenerates the results dict from the committed fixed seeds via run_experiments.run_all() and asserts it matches data/results.json. The stochastic CA curves are compared bit-for-bit (every transition is a PCG64 draw against a constant probability plus an exact integer infected-neighbour test, so they reproduce exactly across platforms and numpy versions); the solve_ivp-derived ode_validation block is compared to a 1e-6 relative tolerance; the non-deterministic speedup timings and generated_at timestamp are excluded.
• Dashboard smoke test (tests/test_app.py) — a headless streamlit.testing.v1.AppTest runs app.py end-to-end (loading the results, rendering all three tabs, executing one live simulation) and asserts it finishes without an uncaught exception. This catches the class of breakage the use_container_width deprecation caused previously.
• CI Python matrix — CI now runs on 3.10 / 3.11 / 3.12 (was 3.12 only), matching the declared target-version = "py310".
• Docs & types — a dedicated ## Installation section in the README (de-duplicating the repeated pip install lines in "Running Locally"), a CITATION.cff so GitHub shows a "Cite this repository" button, and the two missing type hints flagged in ode_reference.py (foi, _interior_counts).

Verification

• ruff check . clean; pytest -q → 43 passed locally (Python 3.13, numpy 2.4.6, scipy 1.17.1, streamlit 1.58.0).
• Confirmed the reproducibility test is not vacuous: a one-cell perturbation fails the strict check and a 1% perturbation fails the tolerance check, while identical data passes.
• Confirmed data/results.json is unmodified after running the suite.

🤖 Generated with Claude Code