Why is the dry/wet parameter for effects -1 to 1 instead of 0 to 1?

As the the title states, I've noticed that Wet/Dry knob with every plugin effect has a range of -1 to 1. Is there a particular reason for this? Numerically, it makes more sense to have this parameter be 0 to 1 where 0 = all dry and 1 = all wet. It would also save a computational step of scaling. If you don't scale the bipolar range, you end up getting 1 = all wet, 0 = all dry, -1 = all wet, with inverted, -0.5 = 50/50 with inverted phase.

No files, tests, or entry points are named. Start by reviewing the issue discussion and tracing how Wet/Dry parameters are defined across plugin effects. Done requires an agreed parameter convention and a clearly scoped change covering the affected effects.

Written by the indexing model from the issue text.