Every --gen-texture-* and --gen-mesh-* handler had its own
copy of the same 3-line "if there's another arg AND it
doesn't look like a switch, parse it; otherwise keep the
default" block. 458 sites across cli_gen_texture.cpp and
cli_gen_mesh.cpp duplicated this pattern.
Hoist into cli_arg_parse.hpp as inline parseOpt{Int,Float,Uint}
(int& i, int argc, char** argv, T& value). Each call site
collapses from 3 lines to 1:
if (i + 1 < argc && argv[i + 1][0] != '-') {
try { width = std::stof(argv[++i]); } catch (...) {}
}
becomes
parseOptFloat(i, argc, argv, width);
cli_gen_mesh.cpp drops by ~250 lines, cli_gen_texture.cpp
by ~430 lines. Output bytes verified identical: firepit
default-arg surface area 2.1100 m² unchanged.
Future texture/mesh primitives now opt in by including one
header instead of pasting the lambda.
