Design by Contract in Go: Panics, Preconditions, and checkContracts()

How panic for programming errors, error for user input, CONTRACT comments, checkContracts() invariant methods, and sorted-slice preconditions create a defense layer that catches bugs before they corrupt security verdicts. Your function receives a time value. It computes a duration. The duration is negative. The comparison says "exposure is less than the threshold." The control passes. The bucket is public. The security verdict is wrong. This happened because the caller passed now as a time befor