fix: better event handling

[Rich-Harris]

Found a couple of bugs in our event handling code, and in the process of fixing them concluded that the whole thing needed overhauling. There's lots of entangled logic and hard-to-follow indirection. Not yet completely happy with it but it's a lot better than it was

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🦋 Changeset detected

Latest commit: 986b048

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[trueadm]

It looks pretty good so far. Maybe you can make it ready for review and merge what we have already to unblock other work? I don't like keeping large refactors open as they block other work.

[Rich-Harris]

yeah, that's fine — had hoped to get a bit more time to work on it before that would become a concern, but the days are short