feat(broadcasts): add duplicate endpoint

[gabrielmfern]

Adds resend.Broadcasts.duplicate(id) and duplicate_async(id) for POST /broadcasts/{id}/duplicate, the endpoint added in resend/resend-openapi#115, ported from the Node method resend.broadcasts.duplicate(id). The release carries 2.45.0.

Two things an adversarial review pass wanted gone that stayed on purpose: the one-line behavior note in the docstrings (Templates.duplicate carries the same kind of note) and the async no-content test (every other endpoint in this file has one). Happy to drop either if you disagree.

Live call against staging through the new method, duplicating e6bd3843-3cc7-4c0d-b7fd-e01cbb514a16, then reading the copy back and deleting it. http_headers elided from the first line.

dup.py

import resend

source = "e6bd3843-3cc7-4c0d-b7fd-e01cbb514a16"
duplicated = resend.Broadcasts.duplicate(source)
print(duplicated)
assert duplicated["object"] == "broadcast"
assert duplicated["id"] != source
copy = resend.Broadcasts.get(duplicated["id"])
print("name:", copy["name"], "| status:", copy["status"], "| subject:", copy["subject"])

{'object': 'broadcast', 'id': 'e1dd9c48-da27-4d59-9f24-0d95a1702b1d', 'http_headers': {...}}
name: Untitled (copy) | status: draft | subject: Another day another test

$ http DELETE https://api.resend-staging.com/broadcasts/e1dd9c48-da27-4d59-9f24-0d95a1702b1d
{"object":"broadcast","id":"e1dd9c48-da27-4d59-9f24-0d95a1702b1d","deleted":true}

🤖 Generated with Claude Code

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Summary by cubic

Adds duplicate() and duplicate_async() to Broadcasts for POST /broadcasts/{id}/duplicate. Duplicating a broadcast creates a new draft with the same content and " (copy)" appended to its name.

• The new methods return the duplicated broadcast's ID and object type.
• The SDK version is bumped to 2.45.0.
• Tests and a usage example cover both sync and async paths, including the no-content error case.

^{Written for commit 1412d51. Summary will update on new commits.}

[cubic-dev-ai]

cubic analysis

All reported issues were addressed across 5 files

Linked issue analysis

Linked issue: DEV-2092: Python SDK (internal, squad-devtools)

Status	Acceptance criteria	Notes
✅	Implement the broadcasts duplicate endpoint in the Python SDK, including synchronous and asynchronous methods.	The diff adds Broadcasts.duplicate and duplicate_async using POST /broadcasts/{id}/duplicate, with response typing and coverage for both paths.
✅	Release the implementation.	The package version is updated from 2.44.0 to 2.45.0.

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