Add diagram workbench UI with Modelica DoF coaching and ISO glyphs.

Ship the Next.js cycle editor with CAD chrome, technical HX symbols, Fixed/Free boundary guidance, and secondary water/air pressure drop support in the solver stack.

Co-authored-by: Cursor <cursoragent@cursor.com>

crates/solver/tests/jacobian_freezing.rs

@@ -7,11 +7,10 @@
 //! - AC #4: Backward compatibility — no freezing by default
 
 use approx::assert_relative_eq;
-use entropyk_components::{
-    Component, ComponentError, JacobianBuilder, ResidualVector, StateSlice,
-};
+use entropyk_components::{Component, ComponentError, JacobianBuilder, ResidualVector, StateSlice};
 use entropyk_solver::{
     solver::{JacobianFreezingConfig, NewtonConfig, Solver},
+    system::DEFAULT_MASS_FLOW_SEED_KG_S,
     System,
 };
 
@@ -37,8 +36,10 @@ impl Component for LinearTargetSystem {
         state: &StateSlice,
         residuals: &mut ResidualVector,
     ) -> Result<(), ComponentError> {
+        // CM1.2: per-edge state is (ṁ, P, h); skip ṁ at index 0 so equation i
+        // targets global state index i+1 (P, h, …).
         for (i, &t) in self.targets.iter().enumerate() {
-            residuals[i] = state[i] - t;
+            residuals[i] = state[i + 1] - t;
         }
         Ok(())
     }
@@ -49,7 +50,7 @@ impl Component for LinearTargetSystem {
         jacobian: &mut JacobianBuilder,
     ) -> Result<(), ComponentError> {
         for i in 0..self.targets.len() {
-            jacobian.add_entry(i, i, 1.0);
+            jacobian.add_entry(i, i + 1, 1.0);
         }
         Ok(())
     }
@@ -82,8 +83,9 @@ impl Component for CubicTargetSystem {
         state: &StateSlice,
         residuals: &mut ResidualVector,
     ) -> Result<(), ComponentError> {
+        // CM1.2: skip ṁ at index 0; equation i targets global state index i+1.
         for (i, &t) in self.targets.iter().enumerate() {
-            let d = state[i] - t;
+            let d = state[i + 1] - t;
             residuals[i] = d * d * d;
         }
         Ok(())
@@ -95,10 +97,10 @@ impl Component for CubicTargetSystem {
         jacobian: &mut JacobianBuilder,
     ) -> Result<(), ComponentError> {
         for (i, &t) in self.targets.iter().enumerate() {
-            let d = state[i] - t;
+            let d = state[i + 1] - t;
             let entry = 3.0 * d * d;
             // Guard against zero diagonal (would make Jacobian singular at solution)
-            jacobian.add_entry(i, i, if entry.abs() < 1e-15 { 1.0 } else { entry });
+            jacobian.add_entry(i, i + 1, if entry.abs() < 1e-15 { 1.0 } else { entry });
         }
         Ok(())
     }
@@ -366,7 +368,7 @@ fn test_jacobian_freezing_already_converged_at_initial_state() {
     let mut sys = build_system_with_linear_targets(targets.clone());
 
     let mut solver = NewtonConfig::default()
-        .with_initial_state(targets.clone())
+        .with_initial_state(vec![DEFAULT_MASS_FLOW_SEED_KG_S, targets[0], targets[1]])
         .with_jacobian_freezing(JacobianFreezingConfig::default());
 
     let result = solver.solve(&mut sys);