Moderation actions start expiring after acknowledgement

[BElluu]

Closed #624

Preview showing the operation of the mechanism with a user login simulation: https://streamable.com/qitpvu

[Teifion]

I've checked with the moderation team and this issue may be out of date, please hold fire on it for now.

I will try to make time to remove any no-longer-relevant issues as I can see you are making steady progress on them :)

[BElluu]

I fix some things from review + nil (empty) duration is Permament.

[Teifion]

I've chased the moderation team regarding a decision on this and they have promised to get back to me today or tomorrow. Apologies again for the delay on this.

[BElluu]

No problem. We do not need to rush :)

[PtaQQ]

Thanks for your patience, and sorry for the delay while we aligned internally.

The conclusion is to narrow this PR’s scope for now:

• Apply the acknowledgement-based expiry behaviour to Warning reminders only. A warning reminder should remain active until it has been acknowledged, using the existing acknowledgement mechanism.
• Do not change expiry behaviour for other moderation restrictions/actions in this PR. That needs to be decided alongside broader changes to notification flow, the public moderation log, and the future client UI.
• It would be good for the implementation to remain reasonably extensible so we can apply similar behaviour to other actions later, but that is not a requirement for this PR.

As a small follow-up, it would be nice to support warning reminders that expire immediately once acknowledged, rather than needing a token duration such as one second. That is non-blocking, though.

Thank you again for the work on this and let me know if there are any additional questions.

[BElluu]

Sounds good. Let me handle it at the end of this week. If I will have any question, I will catch you on discord :)

[Teifion]

Thanks for the response PtaQQ.

As a small follow-up, it would be nice to support warning reminders that expire immediately once acknowledged, rather than needing a token duration such as one second. That is non-blocking, though.

I would suggest that goes into a separate PR.