Debugger for Miri

Miri finds undefined behavior but can't explain why, its only debug aid is thousands of lines of interpreter logs. The original Priroda step debugger bitrotted from tight coupling and no CI. This project rebuilds Priroda with a three-tier architecture: a Miri integration layer, a stable core debugger API (step, breakpoints, locals, allocations, threads), and a DAP server giving any modern editor step-debugging support. It lives inside the Miri repo with CI and scripted tests to prevent future bitrot.