Moves the exhaustive CmdResult router and its 116 handlers out of a single file into command_driver/: thin router stays in mod.rs (no wildcard, compiler-enforced coverage); handlers grouped by domain (entity_commit, clipboard, property_match, modify, solid3d, transform, viewport, text_edit, constraint, dim_edit); shared helpers in utilities/parameters; tests in tests.rs. All moves verbatim 1:1; all entry-point signatures and visibilities unchanged, so every existing caller (ribbon, commands, headless, plugins) resolves untouched.
