so the wallet event specifies that wallet's relays

token events are stored on those relays

nut zaps are published on relays following the outbox model, since it's a message from sender to receiver

so imagine this:

you create Wallet A, you designate that wallets relays to be wss://umbrel.local -- only you have access to read/write on that relay

I send you a nut zap -- I check your outbox relays, which are some publcly accessible relays

I publish the nut zap there, pubkey-locked, unencrypted

once you swap it, you encrypt the new token and save it on wss://umbrel.local 

 With this process, what info is an external "attacker" able to get from looking at the relays where the tokens are being posted?
Only who is receiving those ecash? Other info about the "payment"?