Documentation and packaging release. No change to the importable API. Sphinx documentation site published on Read the Docs, with a statement of need and operating-envelope sections. Documentation built in CI on pushes and pull requests (sphinx-build with warnings-as-errors). [project.optional-dependencies] so pip install fft-cnr[dev] works without uv; expanded [project.urls] (Homepage, Documentation, Issues, Changelog). CNR definition clarified (contrast over noise, dropping the "peak-amplitude SNR" framing) and the 1-D profile scope stated explicitly. Full changelog: https://github.com/thiebes/fft-cnr/blob/main/CHANGELOG.md