Rewind through the descent history (#114)

You can now rewind through the descent history of the last realization using the *Step* control that's been added to the diagnostics panel.

The starting value of the *Step* control depends on the realization status. After a successful realization, we show the realized state (the last step). After an unsuccessful realization, we show the initial guess (step zero).

Co-authored-by: Aaron Fenyes <aaron.fenyes@fareycircles.ooo>
Reviewed-on: #114
Co-authored-by: Vectornaut <vectornaut@nobody@nowhere.net>
Co-committed-by: Vectornaut <vectornaut@nobody@nowhere.net>

app-proto/src/engine.rs

@@ -353,7 +353,7 @@ fn seek_better_config(
 
 // a first-order neighborhood of a configuration
 pub struct ConfigNeighborhood {
-    pub config: DMatrix<f64>,
+    #[cfg(feature = "dev")] pub config: DMatrix<f64>,
     pub nbhd: ConfigSubspace,
 }
 
@@ -388,7 +388,7 @@ pub fn realize_gram(
     if assembly_dim == 0 {
         let result = Ok(
             ConfigNeighborhood {
-                config: guess.clone(),
+                #[cfg(feature = "dev")] config: guess.clone(),
                 nbhd: ConfigSubspace::zero(0),
             }
         );
@@ -509,7 +509,7 @@ pub fn realize_gram(
         // find the kernel of the Hessian. give it the uniform inner product
         let tangent = ConfigSubspace::symmetric_kernel(hess, unif_to_std, assembly_dim);
         
-        Ok(ConfigNeighborhood { config: state.config, nbhd: tangent })
+        Ok(ConfigNeighborhood { #[cfg(feature = "dev")] config: state.config, nbhd: tangent })
     } else {
         Err("Failed to reach target accuracy".to_string())
     };