simpleaf 0.27.0 (new formula)

[BenjaminDEMAILLE]

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• I did not use AI/LLM to create this PR, or I disclosed the tool/model below and reviewed its output; I did not attribute commits to AI and will answer maintainer questions and review comments myself without AI/LLM.

AI-assisted contribution by Claude Code (Claude Opus 5) of ~85% of the work: the AI wrote the formula and ran brew install --build-from-source, brew test, brew audit --new --strict --online and brew style. I reviewed the formula and those results before opening this PR. The commit carries no AI attribution trailer.

Built and tested locally on macOS 26.6.1 running arm64.

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New formula for simpleaf, the COMBINE-lab workflow driver for single-cell/single-nucleus RNA-seq and scATAC preprocessing (companion to alevin-fry, already in core).

brew audit --new --strict --online reports one remaining problem:

* GitHub repository not notable enough (<30 forks, <30 watchers and <75 stars)

The repo is at 67 stars / 6 forks. Submitting anyway because the tool is published and peer-reviewed (Bioinformatics, 2023: btad614) and is packaged in Bioconda; happy to close if the maintainers would rather wait for the star threshold.

Two notes on the formula:

• depends_on "cmake" => :build is required because anndata-hdf5 enables hdf5-metno-sys's static feature unconditionally, so HDF5 is always built from vendored sources.
• ENV["CC"]/ENV["CXX"] are set to the real compilers: the vendored HDF5 build records CMAKE_C_COMPILER in its build-settings blob, which otherwise leaves Homebrew shim paths in the binary.

No runtime depends_on on the mappers: simpleaf resolves piscem/alevin-fry via simpleaf set-paths at runtime, piscem is not in core, and core's alevin-fry 0.16.2 is below simpleaf's >=0.17.0 floor. Can follow up with a piscem formula and an alevin-fry bump in separate PRs if wanted.