Add per-message TTL support

[caspervonb]

No description provided.

[Copilot]

Pull Request Overview

This PR adds support for per-message Time-To-Live (TTL) functionality, a feature introduced in NATS Server 2.11+. The implementation allows clients to specify a TTL for individual messages published to JetStream streams that have the allow_msg_ttl option enabled.

Key changes:

• Added msg_ttl parameter to publish() and publish_async() methods for setting per-message TTL in seconds
• Added allow_msg_ttl configuration option to StreamConfig for enabling per-message TTL on streams
• Added comprehensive test coverage verifying TTL behavior including message expiration and stream state updates

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
nats/src/nats/js/api.py	Added MSG_TTL header constant and allow_msg_ttl stream configuration field
nats/src/nats/js/client.py	Implemented msg_ttl parameter in publish methods with nanosecond conversion logic
nats/tests/test_js.py	Added comprehensive test validating TTL functionality with multiple expiration scenarios

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[Copilot]

Pull Request Overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

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[wallyqs]

LGTM