Add cellpin to scverse ecosystem

[philinscience]

Name of the tool: cellpin

Short description: cellpin is a lightweight probabilistic model that reconstructs and denoises spatial transcriptomes from single-cell RNA-seq references. It enables transcriptome-wide imputation, robust atlas-to-spatial label-transfer, and improved biological interpretation of both targeted-panel and full-transcriptome spatial datasets.

How does the package use scverse data structures (please describe in a few sentences): cellpin uses AnnData as its native input and output format for both scRNA-seq references and spatial transcriptomics data. It also supports SpatialData tables, aligning genes across these objects and writing imputed expression, embeddings, and annotations back into scverse-compatible containers.

• The code is publicly available under an OSI-approved license
• The package provides versioned releases
• The package can be installed from a standard registry (PyPI)
• Automated tests cover essential functions of the package and a reasonable range of inputs and conditions
• Continuous integration (CI) automatically executes these tests on each push or pull request
• The package provides API documentation via a website or README
• The package uses scverse datastructures where appropriate (AnnData and SpatialData)
• I am an author or maintainer of the tool and agree on listing the package on the scverse website