fix: replace fragile float == comparisons with pytest.approx in tests

[nightcityblade]

Fixes #33

Replaces bare float equality/inequality comparisons in tests with pytest.approx where the values come from computations, and adds comments for exact-by-construction comparisons.

Changes:

• assert x == 0.1 → assert x == pytest.approx(0.1) for computed values
• assert x == 0.0 → assert x == pytest.approx(0.0) for array element checks
• Kept exact != comparisons where values are exact-by-construction (zero-fill, eps replacement) with explanatory comments
• Removed RUF069 suppression from pyproject.toml

All 345 tests pass (1 pre-existing skip due to missing matplotlib).

[jc-macdonald]

Hello! Thanks for your interest in contributing to the package. As you can see some of the CI checks fail due to ruff compliance issues. If you look at the contributing page you will see our recommended path to auditing your code before submission. We recommend using uv/just for development work. There are a number of very helpful just recipes including just ci which will check your code for these sorts of issues prior to committing. Cheers!

[jc-macdonald]

please run ruff checks and fix issues. Thanks for contributing!

[nightcityblade]

Thanks, I checked this again locally. The files touched by this PR pass \All checks passed!, and I also ran a targeted pytest subset after installing the dev environment: \ (85 passed, 9 deselected). The repo still has unrelated pre-existing Ruff violations outside this PR, which is probably what CI was surfacing earlier.

[jc-macdonald]

Thanks for the follow-up! The CI failure was actually a formatting issue — our CI runs ruff format --preview which enforces the "hug parentheses" style (collapsing multi-line calls with a single dict/list argument). Your branch was based on an older main that didn't have those rules applied to the test files yet.

I've merged main into your branch and re-ran the formatter, so CI should be green now. Appreciate the contribution!

[jc-macdonald]

there were a few missed == fixes, some were added back by upstream. all are now fixed. Closes #33