Canadian partner here.
At least for in Canada, any shift 5 hours or longer you are required to get an unpaid half. That being said, your SSV is correct in that if your shift is 4 hours and 59 minutes, you technically do not need a half. The minute you hit that 5 hour mark you would be in lunch violation, but provided you punched out early, you’re on the clear. That being said, if you are scheduled for 4-9, the expectation is that you are punching accurately and taking your half as you had been scheduled as that extra half hour that you are now getting paid for will affect your store’s labour. But the bottom line is, your SSV made a call and as a SSV they’ll have to take responsibility for their decision - whether it was the right or wrong one will be between them and your manager. You don’t have to worry one bit about getting them in trouble, as it’s their responsibility to make the right calls for their store when your manager isn’t there, and they’re the one who will answer for the calls that they make. So I say don’t fret it one minute longer! ✌🏻

As long as you punched in &out for less than a total of 5 hours, you're okay. If you do 5:01 you'll get paid one of those hours as OT, the shift will get a stern lecture, and the SM will get a stern email. (For example: I got a stern lecture today)

If you’re working from 4-9 you wouldn’t get a lunch anyway unless you’re a minor.

Depends on what state you are in I think, I know for me I was told as a shift that I have to give someone their lunch at 4hours and 45 min. So that there is a cushion so that they don’t meal violate which is at 5 hours. So technically your shift lead was correct. And you should be fine. Hopefully this helped a little.

You mentioned you from CA? If so you definitely are in violation. But it’s more on the SSV not on you. You are allowed to work a maximum of 4.5 before you start to void. I always pay attention to this or if they looking to cut labor to just give me a 10 and let me work for 4.5 hours if I’m doing a coverage. And was schedule to do a 7 hour shift.

Usually you need to take a lunch if you have an 8 shift you are required to take a lunch before 5 hours. I think you should be in the clear. But if I am wrong please someone correct me!!