fix(model): restore saved solid booleans

Reload exact B-reps from solid history or ACIS before model operations and pin the closed-cut kernel fix.

src/modules/model/boolean_cmd.rs

@@ -1,6 +1,6 @@
 // Boolean operations on 3D solids (Design group). The actual CSG runs in
 // `App::solid_boolean` (src/app/model_ops.rs) using the kernel on the
-// session-cached B-reps; this module just names the operations.
+// cached B-reps; this module just names the operations.
 
 /// Which boolean a Design-group tool performs on the two selected solids.
 #[derive(Clone, Copy, PartialEq, Eq, Debug)]