feat(components): add ThermoState generators and Eurovent backend demo

crates/fluids/Cargo.toml

@@ -0,0 +1,28 @@
+[package]
+name = "entropyk-fluids"
+version.workspace = true
+authors.workspace = true
+edition.workspace = true
+license.workspace = true
+repository.workspace = true
+description = "Fluid properties backend for Entropyk thermodynamic simulation library"
+
+[dependencies]
+entropyk-core = { path = "../core" }
+thiserror.workspace = true
+serde.workspace = true
+serde_json = "1.0"
+lru = "0.12"
+entropyk-coolprop-sys = { path = "coolprop-sys", optional = true }
+
+[features]
+default = []
+coolprop = ["entropyk-coolprop-sys"]
+
+[dev-dependencies]
+approx = "0.5"
+criterion = "0.5"
+
+[[bench]]
+name = "cache_10k"
+harness = false