pizzarr

• zarr_open() on an s3:// or gs:// string fell through to DirectoryStore, which tried to create a directory named after the URL. These URLs now resolve to S3Store and GcsStore, and cloud stores default to read mode.
• S3Store and GcsStore inherited no-op get_item(), contains_item(), and listdir() methods that silently returned NULL. They now raise an error naming the supported read paths.
• HttpStore$listdir() took no arguments, so the path argument every other store accepts raised an error that callers swallowed --- ZarrGroup's print method reported No. members : 0 for every HTTP-backed group. It now accepts path and lists within it.

Documentation

• New vignettes/remote-stores.Rmd covering remote and cloud access: the mapping from fsspec/xarray storage_options to pizzarr's environment variables, the HTTPS and s3:// routes, alternate endpoints such as MinIO, Ceph, and Open Storage Network pods, and the current limits.
• Alternate S3 endpoints are configured with AWS_ENDPOINT; AWS_ALLOW_HTTP and AWS_VIRTUAL_HOSTED_STYLE_REQUEST cover plain-HTTP and path-style addressing. This worked before but was undocumented.
• Anonymous access to public GCS buckets over gs:// is documented, and now tested. It needs GOOGLE_SKIP_SIGNATURE=true, since GCS does not infer anonymous access from absent credentials the way S3 does.
• S3Store, GcsStore, and HttpStore gained detailed documentation of credentials, endpoints, and which distribution tier each requires.
• zarr_open()'s store argument now documents every accepted form: a path, an http(s):// URL, an s3:// or gs:// URL, or a Store object.
• zarr_open_group()'s storage_options argument is documented as ignored rather than as an fsspec passthrough.
• Vignettes reorganized around data conventions rather than transport, now that connection details have their own article. remote-ome-ngff.Rmd merged into ome-ngff.Rmd, which covers the OME-NGFF multiscales convention against both a local and a remote store; remote-anndata.Rmd renamed anndata.Rmd.
• The OME-NGFF and AnnData vignettes now evaluate their code at build time instead of showing static listings, so the examples are checked. Both require the blosc package and network access, and degrade to unevaluated when either is missing.
• README gained a "Remote and cloud data" section.