Revert #1682 (three-axis milling) (#1715)

Thanks @bherbruck.

crates/engine/src/lib.rs

@@ -14,8 +14,6 @@ pub mod crash;
 pub mod frames;
 pub mod fuzz;
 pub mod licences;
-pub mod manufacturing;
-pub use solidcraft_cam as cam;
 pub mod occurrences;
 pub mod params;
 pub mod product_scene;
@@ -254,8 +252,6 @@ pub struct Session {
     /// Host-owned viewport metadata, never saved or included in history.
     render_viewport: Option<Arc<render::ExecutorDescriptor>>,
     render_jobs: render_jobs::Jobs,
-    /// Derived, immutable CAM jobs; not persisted or copied into undo snapshots.
-    pub cam_jobs: manufacturing::Jobs,
     /// The visibility the design file holds (what `is_dirty` compares with).
     saved_visibility: Visibility,
     /// States to go back to (`edit.checkpoint`, `edit.restore_checkpoint`): how batches of
@@ -381,7 +377,6 @@ impl Session {
             camera: None,
             render_viewport: None,
             render_jobs: Default::default(),
-            cam_jobs: Default::default(),
             #[cfg(test)]
             evaluations: 0,
             crash_journal: false,
@@ -849,7 +844,6 @@ impl Session {
             camera: self.camera,
             render_viewport: self.render_viewport.clone(),
             render_jobs: self.render_jobs.scratch(),
-            cam_jobs: Default::default(),
             saved_visibility: self.saved_visibility.clone(),
             #[cfg(test)]
             evaluations: 0,