Store rat weight (over time?)

[Rory-Reid]

This feedback has come in twice now, once on the forums and once when discussing the breeder spreadsheet.

On the forums the feedback was that it doesn't need to be anything fancy and can just be a constantly editable value. If constantly editable, perhaps this calls for a "weighed at" date alongside it.

However when discussing the spreadsheet it's clear there's a lot more room for something bigger here. Consider the specifics of the spreadsheet but the general gist is that rat weights are logged against specific ages prompting breeders to track it over time at consistent intervals. The ages also go beyond dates when rats would be typically homed out, so it's worth considering what to do there (do breeders ask their homes for weights? Do they want reminders? Do they want weights to disappear from this point?).