sdks: add zip archive format option

[claude]

Requested via Slack thread

Before

repo.getArchiveStream() / repo.get_archive_stream() / repo.ArchiveStream() could only download a gzipped tar. A customer who wanted a zip had to unpack the tar and re-zip it themselves.

After

All three SDKs take an optional archive format. Ask for zip and the response streams a zip archive (Content-Type: application/zip, suggested filename <name>-<ref>.zip) instead of gzipped tar (Content-Type: application/gzip, <name>-<ref>.tar.gz).

// TypeScript
const resp = await repo.getArchiveStream({ ref: 'main', format: 'zip' });

# Python
resp = await repo.get_archive_stream(ref="main", format="zip")

// Go
resp, err := repo.ArchiveStream(ctx, storage.ArchiveOptions{Ref: "main", Format: storage.ArchiveFormatZip})

Leaving the option unset is unchanged: no format key is sent at all, so existing callers produce byte-identical requests and keep getting tar.gz.

How

The archive endpoint gains an optional top-level format field in its JSON body, accepting "tar.gz" (the default) or "zip". Each SDK exposes it in that package's idiom for enum-ish options:

• Go — ArchiveFormat string type with ArchiveFormatTarGz / ArchiveFormatZip constants, plumbed through ArchiveOptions.Format into archiveRequest with json:"format,omitempty".
• TypeScript — ArchiveFormat = "tar.gz" | "zip" string-literal union, ArchiveOptions.format, serialized only when non-empty.
• Python — ArchiveFormat = Literal["tar.gz", "zip"], keyword-only format argument on get_archive_stream and the Repo protocol.

READMEs in all three packages show requesting a zip and note the resulting content type and filename. skills/code-storage/SKILL.md gets the same for the raw endpoint (format in the body, plus the endpoint-table row).

Tests in each package cover: format serializes into the request body when set, is absent when unset, and a zip response is handed back with Content-Type: application/zip.

No version bump — releases are cut separately.

Depends on the server-side format support landing in pierredotco/monorepo; until then "zip" will be ignored or rejected by the API.

Closes CSW-533.

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Generated by Claude Code

[notion-workspace]

#ext-lovable-pierreSupport zip format for archive endpoint