Highlight age of old boosts

### Problem I have

People sometimes boost toots from a long time ago. And while the date is of course included, it can be easy to miss. The context of a toot from the last week is very different than one from last year or more. It would help to flag these kind of necro-boosts, for example, similar to the way that The Guardian puts a prominent "This Article in N months old" on articles past a certain time.

### Solution I'd like

The option for the date of old (more than 2 weeks? 1 month?) boosted toots to be highlighted more prominently. Perhaps by making them red, or even just a red "!" or "⚠" in front of them.

### Alternatives considered

_No response_

### Other

_No response_