refactor(editor): extract WOM <-> OBJ/GLB/STL into cli_wom_io.cpp

Moves the four WOM interchange-format handlers (--export-obj,
--export-glb, --export-stl, --import-stl) out of main.cpp into
a new cli_wom_io.{hpp,cpp} module. WOM is our open M2
replacement; these are the bridge that lets it round-trip
through every external 3D tool — Blender, Three.js, slicers,
CAD packages — so the open format is actually useful.

main.cpp shrinks by 467 lines (9,464 to 8,997). The five WOB
and WHM exporters (--export-wob-glb, --export-whm-glb, etc.)
remain inline for a follow-up extraction.

tools/editor/cli_wom_io.hpp

@@ -0,0 +1,20 @@
+#pragma once
+
+namespace wowee {
+namespace editor {
+namespace cli {
+
+// Dispatch the WOM <-> interchange-format handlers. WOM is our
+// open M2 replacement; these export it to / import it from the
+// formats every other 3D tool understands:
+//   --export-obj     WOM -> Wavefront OBJ (universal text format)
+//   --export-glb     WOM -> glTF 2.0 binary (browsers, Three.js)
+//   --export-stl     WOM -> ASCII STL (slicers / 3D printers)
+//   --import-stl     ASCII STL -> WOM (round-trip from CAD tools)
+//
+// Returns true if matched; outRc holds the exit code.
+bool handleWomIo(int& i, int argc, char** argv, int& outRc);
+
+} // namespace cli
+} // namespace editor
+} // namespace wowee