https://duckduckgo.com/?t=ffsb&q=smoke+sensor+smoking+fee&ia=web shows a few hits including https://www.freshairsensor.com/blog_credit_card_chargebacks/ suggesting this is a real thing.

You might ask them for the exact time(s) the smoking incidents allegedly occurred and see if that helps. You could also try filing a chargeback despite what the URL above says.

Apparently, smoke sensors are also used by car rental places and Air B&Bs

This statement is incorrect. Your credit score looks at utilization: how much credit you're using divided by how much credit you have available.

Even if you pay off your card monthly, the utilization is calculated at the time your credit report is pulled, so it's not always 0% even if you pay completely every month

Go to https://treasurydirect.gov/savings-bonds/i-bonds/ but read the terms carefully. The interest rate is ~10% for 6 months, but you lose 3 months of interest (or something) if you cash the bond in prior to 5 years (or something-- don't rely on what I'm saying here-- read for yourself), so it might not be as good a deal as it seems. The bond is "inflation indexed" so, if inflation decreases, the return after 6 months will go down.

Are you asking how many days from perihelion Mercury was on Oct 9th 2006? Some people define "start of orbit" as perihelion (closest to Sun), especially when using elliptical parameters, but there are other ways to define "start of orbit" too