Question #1:
OP, you say your wallet is older than when you started using Rewind.ai. After you started using that tool, did you ever display your private keys or your mnemonic recovery words of your wallet on screen so that such sensitive details could've been recorded by Rewind.ai?
Think hard and try to remember any possibility for such to happen.

You say Rewind.ai stores recordings only on your local device. Question #2: how are such recordings secured? Any encryption or password necessary to replay such recordings? (I don't know this tool.)

Question #3: have you ever granted someone remote access to your device? Do you have remote access tools installed, like TeamViewer, Anydesk, ...?

Question #4: I assume your MacBook wasn't ever in any repair shop or Apple repair while there's still your data on it and since you have your wallet active? (Just to exclude the most obvious things.)

My brainstorming is about how could your wallet's sensitive data leaked. You didn't say or answer anything about browser extensions. Is this Bitcasino only a website or did you install some software from them on your device?

Pmalek's idea that the stealing transaction could be somehow related to your transfer to Kraken is a path worth to explore but frankly I don't have an idea how this could lead to a leak of data allowing a malicious party to transfer your funds.

Problem is also that is not going to be easy to determine if your device is clean or infected with something malicious.