In my mind, "consulting" is knowledge work. Your role is to lend knowledge and expertise, help with strategy, architecture, tool/platform selection, etc.
"Contracting" is high-skill grunt work. Your role is to code your fingers off, deliver-deliver-deliver, typically according to someone else's (possibly ill-conceived) plan.
Have these things truly become synonymous?
The former is an activity and the latter is a business relationship, so they're orthogonal. Many consultants are contractors but not all are. Many contractors sell consultancy but not all do.
Not at all. Contracting, in itself, is just the business agreement but most of the time contractors are experts and have plenty of autonomy.
The very opposite of grunt work.
Even so, I try to ensure that my contracting engagements demonstrate my value as a consultant.