feat(webhooks): add support for topic and contact.topics.updated events

[joaopcm]

the API accepts contact.topics.updated, topic.created, topic.updated and topic.deleted as webhook events, and they're live with no feature flag (the monorepo has sent them since at least 60ac6d5dbf, 2026-02-12). resend.Webhooks doesn't list them and WebhookEventPayload has no types for them.

this adds them to the event list in _webhook.py, adds ContactTopicsEventData, ContactTopicSubscription, TopicEventData, ContactTopicsUpdatedEvent, TopicCreatedEvent, TopicUpdatedEvent and TopicDeletedEvent, and exports them. topics items are a new ContactTopicSubscription, with subscription typed as Literal["opt_in", "opt_out"].

payloads, from topic-events-webhook.ts and contact-events-webhook.ts in the monorepo:

• contact.topics.updated: email, and topics, the topics changed in that update, each with its new subscription (opt_in or opt_out)
• topic.created, topic.updated, topic.deleted: id, name, description (string or null), default_subscription (opt_in or opt_out), deleted, created_at, updated_at

bumps to 2.49.0.

flake8 and pytest (699 passed) pass. mypy has 2 errors, both Unused "type: ignore" in tests/exceptions_test.py:136,139, and main has the same 2.

[cubic-dev-ai]

All reported issues were addressed across 4 files

<sub>Reply with feedback, questions, or to request a fix.

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[klotty]

0 issues found across 2 files (changes from recent commits).

Confidence score: 5/5

• Automated review surfaced no issues in the provided summaries.
• No files require special attention.

<sub>Auto-approved: Adds TypedDicts, event-list entries, exports, and a version bump for four webhook events the API already emits. This is an additive, non-breaking SDK typing change; remaining risk is ordinary typing correctness already covered by Cubic's review.

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