Moves the WOM mesh editing/transform handlers out of main.cpp:
--add-texture-to-mesh --scale-mesh
--translate-mesh --strip-mesh
--rotate-mesh --center-mesh
--flip-mesh-normals --mirror-mesh
--smooth-mesh-normals --merge-meshes
These are the post-generation manipulators (load → mutate → save)
distinct from the geometry generators in cli_gen_mesh.cpp and
the heightmap I/O in cli_mesh_io.cpp.
main.cpp drops 20,741 → 20,005 lines (-736). Behavior verified
by piping a fresh cube through scale → translate → center.
