Anti-duplicate false positives

Hello, we've been experiencing a problem with Vortex's anti-duplicate feature for a while now. Sometimes Vortex will suddenly claim that someone posted the same message multiple times, often across different channels, and strike the user, sometimes more than once. The message log also states that the messages were deleted, but Discord's audit log says Vortex didn't actually delete anything. This has happened even when the users in question weren't even online, and they have confirmed us that they never posted those messages (or at least, not recently).

The content of the messages does look like something they would post more than once over time, such as a gif link, which leads me to believe that Vortex might be including older messages when searching for duplicates.

This is a major problem, since people can be muted or even banned out of nowhere as a result, so I hope it can be investigated and fixed. Thank you.

Start by reproducing the anti-duplicate false positive described in issue #177, including repeated-looking messages across channels and users who are offline. Trace the duplicate search and moderation/logging behavior, then verify that only genuinely new duplicates trigger one action and that the audit log matches the reported action.

Written by the indexing model from the issue text.