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/Cargo.toml

@@ -21,6 +21,12 @@ serde_json = "1.0"
 approx = "0.5"
 serde_json = "1.0"
 tracing-subscriber = "0.3"
+entropyk-fluids = { path = "../fluids" }
+
+[features]
+# Enables the end-to-end emergent-pressure integration test, which needs a
+# CoolProp backend (entropy + saturation) unavailable in the mock/TestBackend.
+coolprop = ["entropyk-fluids/coolprop"]
 
 [lib]
 name = "entropyk_solver"