Following the directions outlined by Apple here, i can confirm that the system itself recognizes my device, but iTunes and (more importantly) Xcode refuse to. I made sure to update everything i could; and since this is a vanilla install, I can think of no "third-party security software" that would conflict. How does one troubleshoot this?
Phone Type: iPhone 6
macOS version: 10.12.6
iOS version: 10.3.3
Full Output of
system_profiler SPUSBDataType: here