chore: harden v0.7 prerelease data contracts

[mwyau]

Summary

• Finished the v0.7 documentation/release-hardening follow-up without changing tracker algorithms or the package version.
• Corrected stale external-data wording; promoted roadmap §§3.1 Xarray generalized ufunc integration, 3.2 Distributed backends, and 5.16 Reduced Gaussian grids to ✅ Implemented based on current code and tests; genuinely incomplete scope remains 🚧.
• Replaced the unsupported roadmap math macro and repaired the Hodges Mermaid diagram with a vertical, readable frame-task/MGE-splice layout.
• Routed the remote-Zarr integration URL through the centralized test-data helper and fixed two documentation cross-references so strict Sphinx builds cleanly.
• Package version remains 0.7.0.dev0.

Why

The pinned external-data contract is now live and used by the test suite. The documentation now distinguishes available ERA5 inputs and routine data/slow selection from the one missing scientific parity product: the NCL-generated VODV reference fields. The roadmap also distinguishes implemented execution boundaries from optional scaling, benchmark, and independent-reference validation work. No algorithm, feature, test-data download, PyStormTracker-Data, or Validation-repository changes are included.

External test-data contract

All network-backed test data access uses the centralized helpers in tests/utils.py and the single pin:

PyStormTracker-Data v0.2.0-data

Both RAW_BASE and RELEASE_BASE are derived from DATA_VERSION; the integration and parity tests do not embed older Data tags or ad-hoc GitHub URLs.

Available assets used or supported by current tests include:

• ERA5 MSLP and VO850, including N320 and regular-grid inputs;
• ERA5 UV850 at 0.25° and 2.5°;
• the raw-Git 2.5° MSLP Zarr store;
• historical v0.0.2 Simple-track references; and
• the 2024 monthly F320 MSLP/VO850 release assets.

Only the required NCL-generated VODV reference fields are missing from v0.2.0-data, so broader NCL/Spherepack kinematics parity remains deferred rather than skipped or replaced with a self-generated reference.

The committed December MSLP input and small NCL T5-42 output remain intentional offline fixtures; they are not alternate external-data pins.

Validation

• uv run pytest -vv tests/unit/test_utils.py — 13 passed
• uv run pytest -vv tests/unit/preprocessing/test_spectral.py — 16 passed
• uv run pytest -vv tests/unit/test_cli.py — 54 passed
• uv run pytest -vv — 521 passed
• uv run pytest -vv tests/integration/ -m "not slow and not data" — 20 passed, 9 deselected
• uv run pytest -vv tests/parity/ -m "not slow and not data" — 1 passed, 2 deselected
• Ruff check/format, ty, and mypy
• sphinx-build -W --keep-going -b html docs docs/_build/html — succeeded with no warnings
• Full CI matrix for new head 55a9f65 — pending; not claimed as passed

No version bump, release tag, PyPI publication, Validation-repository change, or PyStormTracker-Data change is included in this follow-up.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 78.31%. Comparing base (2f00f62) to head (55a9f65).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #200      +/-   ##
==========================================
+ Coverage   77.95%   78.31%   +0.36%     
==========================================
  Files          58       58              
  Lines        9621     9621              
  Branches     1870     1870              
==========================================
+ Hits         7500     7535      +35     
+ Misses       1407     1370      -37     
- Partials      714      716       +2     

Flag	Coverage Δ
integration	51.58% <0.00%> (ø)
parity	17.49% <0.00%> (ø)
unit	57.06% <100.00%> (+0.36%)	⬆️
unit-jit-coverage	72.48% <100.00%> (+0.36%)	⬆️
unit-jit-disabled	73.82% <100.00%> (+0.36%)	⬆️

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

Files with missing lines	Coverage Δ
src/pystormtracker/preprocessing/spectral.py	74.40% <100.00%> (+12.99%)	⬆️
src/pystormtracker/utils/cli.py	85.71% <100.00%> (+4.76%)	⬆️