embedded3: cut predictor convection carries ρ (host + e3_cut.cu; density-scaling pin); operator load route includes the wall exchange (exchange.rs); reconstructed_parts, probe aperture floor knob; dfg_split diagnostic test

Co-Authored-By: Claude Fable 5.1 <[email protected]>

crates/specialized/rtx-cfd/src/solvers/incompressible/embedded3/step/cut_predictor.rs

@@ -201,7 +201,9 @@ impl Solver {
         // control volume (zero for a body at rest, the swept rate
         // otherwise) multiplies the face's own value, so a uniform field
         // stays uniform on any wall motion.
-        conv -= mass_out * u0;
+        // The mass fluxes above are volume fluxes: the momentum flux carries ρ
+        // (inertia, diffusion and the pressure are dynamic).
+        let conv = rho * (conv - mass_out * u0);
         let p_plus = lat.cell(cell_plus).map_or(0.0, |ci| field.p[ci]);
         let p_minus = lat.cell(cell_minus).map_or(0.0, |ci| field.p[ci]);
         let pressure = -(p_plus - p_minus) * cv.alpha * area[c];

crates/specialized/rtx-cfd/src/solvers/incompressible/embedded3/step/mod.rs

@@ -213,6 +213,11 @@ impl Solver {
                 Mask::build_cut_from(body, g, t, self.params.boundaries, prev)
             }
         }
+        .map(|mut m| {
+            m.scheme = self.params.convection_scheme;
+            m.density = self.fluid.density;
+            m
+        })
         .expect("embedded mask")
     }