Stress-tests the iterated preprocessing algorithm on random
maximal-outerplanar triangulations: terminates on n<=60 within bounded
steps, occasionally hits step cap at n=80 with random edge choice.
Scaffolds the user-proposed v_c-rotation algorithm and documents the
monovariant findings (lexicographic depth signature is weakly but not
strictly decreasing under preprocessing).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>