Expose the per-file Downloads API (/v1/downloads) in the SDK

Locate the OpenAPI spec and compare the existing sessions.downloads resource with api.md in the Python and Node SDKs. Add the documented /v1/downloads list, retrieve, and delete operations, and update the session downloads description to identify its zip response. Done means both SDKs expose the generated downloads resource and the session endpoint documents the archive return.

What exists today

The only way to retrieve downloaded files through the SDK is client.sessions.downloads.list(id). It calls GET /v1/sessions/{id}/downloads with Accept: application/zip and hands back the raw response (BinaryAPIResponse in Python, Response in Node): a zip archive containing every file the session downloaded. Nothing in the method's description says so. The generated docstring is just "Session Downloads", so the first hint that you are holding a zip is the response body.

What's missing

Browserbase documents a per-file Downloads API that is not in the SDK at all. Neither SDK has a downloads resource, and api.md in each lists only the zip endpoint and sessions.recording.downloads. The documented endpoints:

• GET /v1/downloads?sessionId=<id> lists individual downloads with id, sessionId, filename, mimeType, size, checksum (SHA-256, hex) and createdAt, plus total / limit / offset for pagination. Optional filters: filename, mimeType, minSize, maxSize, createdAfter, createdBefore, limit (default 20, max 100), offset.
  https://docs.browserbase.com/reference/api/list-downloads
• GET /v1/downloads/{downloadId} returns the metadata above with Accept: application/json, or the file bytes with Accept: application/octet-stream.
  https://docs.browserbase.com/reference/api/get-download
• DELETE /v1/downloads/{downloadId} deletes one download and returns 204.
  https://docs.browserbase.com/reference/api/delete-download

Feature overview: https://docs.browserbase.com/features/downloads

Why it matters

• Per-file access with mimeType and size filters and pagination, instead of one opaque archive per session.
• No zip round-trip when you want a single file: fetch it by id and you are done.
• A caller can gate on one body's magic bytes, or compare size / checksum from the listing, before doing anything with the file.

Our integration ended up dropping the SDK for these calls and using raw httpx against /v1/downloads for exactly these reasons. The client's get() plus make_request_options() covers the gap in the meantime, but it means hand-writing the types the generator would otherwise produce.

Ask

1. Add the three /v1/downloads endpoints to the OpenAPI spec so they generate into both the Python and Node SDKs as a downloads resource (list, retrieve, delete).
2. While there, give GET /v1/sessions/{id}/downloads a description that says it returns a zip archive of all files downloaded during the session, so sessions.downloads.list() documents its return type.