Merge vertices (M) and make face/edge (F). Wired up AobaAPI GlueVert for merge-to-centroid, MakeEdge/MakeFace for filling faces from selected verts or edges, and ManifoldMakeEdge for face splitting (select 2 verts on the same face, F splits it). Replaces the flip normals keybind (now unmapped). Independent plan review caught 3 issues pre-implementation: duplicate vert self-glue, uncaught MakeEdge throws, missing stdexcept include.