Public ROB
An unmodified Pons ERC-20. No transfer hooks, no blacklist, nothing a token scanner would flag.
Shielding
Shielding transfers ROB into the ROBVault and credits shares. Shares are tracked per address in sharesOf; the ROBVault never needs to know which addresses are stealth.
Accounting
The ROBVault tracks totalBacking and totalShares. Every path that moves tokens updates both and emits VaultUpdated, so anyone can audit them.