fix(edit): grip edits drop a dimension's stale baked *D block (#398)

A reopened file renders dimensions from the *D block baked on save, so
grip drags only moved definition points while the stale block kept
drawing — grips worked on fresh dimensions but died after a roundtrip.
Route the grip drag, grip-menu actions and typed grip-menu values
through invalidate_dim_block (#181) so tessellation falls back to live
geometry and the next save re-bakes.

Co-Authored-By: Claude Fable 5 <[email protected]>

src/scene/modify.rs

@@ -391,6 +391,11 @@ impl Scene {
         if let Some(entity) = self.document.get_entity_mut(handle) {
             view::dispatch::apply_grip(entity, grip_id, apply);
         }
+        // A dimension loaded from a file renders through its baked *D block;
+        // the grip only moved a definition point, so the baked graphics are
+        // stale — drop them so tessellation falls back to the live geometry
+        // and the next save re-bakes (no-op for non-dimensions). (#398)
+        crate::modules::draw::modify::explode::invalidate_dim_block(&mut self.document, handle);
 
         // Translate MeshModel vertices by the same delta the grip applied.
         if let Some(old) = old_por {