Holes at sketch points (one feature, many holes, following the points) and threaded holes; cosmetic threads (FusionThreadCommand, ISO metric, model.threads); components groundwork: the document is a component tree (New Component, Create Components from Bodies, active component, component.list)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL

crates/engine/src/cmd/mod.rs

@@ -2,6 +2,7 @@
 //! toolbar placement (`tab`, `panel`) follows Fusion's Design workspace so the registry doubles
 //! as the parity metric (`cargo xtask parity`).
 
+mod component;
 mod edit;
 mod face;
 mod features;
@@ -112,6 +113,7 @@ pub fn command_specs() -> Vec<&'static CommandSpec> {
     v.extend(sketch_modify::COMMANDS.iter());
     v.extend(sketch_project::COMMANDS.iter());
     v.extend(features::COMMANDS.iter());
+    v.extend(component::COMMANDS.iter());
     v.extend(edit::COMMANDS.iter());
     v.extend(file::COMMANDS.iter());
     v.extend(inspect::COMMANDS.iter());