libSceAutoMounterClient technical debt

sceAutoMounterClientRegisterCallback, sceAutoMounterClientTerm and sceAutoMounterClientUnregisterCallback (libSceAutoMounterClient) - their names and NIDs are in the PS5 3.20 export inventory, but no credible prototypes were found. They are declared without parameters solely to resolve known imports; this is not an ABI claim and callers must not call them until signatures are verified.
sceAutoMounterClientGetUsbDeviceInfo: the 22 metadata bytes at offset 128 remain opaque. The 944-byte output layout, 128-byte device name and three 256-byte arrays with 64-bit lengths are recovered.