feat: Adds psi to feet of head conversion.

Sources/Routes/Models/FeetOfHead.swift

@@ -0,0 +1,74 @@
+import CasePaths
+import PsychrometricClient
+@preconcurrency import URLRouting
+
+public enum FeetOfHead {
+  public static let description = """
+  Convert PSI to Feet of Head, to aid in pump flow calculations.
+  """
+
+  public struct Request: Codable, Equatable, Hashable, Sendable {
+
+    public let pressure: Double
+    public let waterTemperature: Double?
+
+    public init(pressure: Double, waterTemperature: Double? = nil) {
+      self.pressure = pressure
+      self.waterTemperature = waterTemperature
+    }
+
+    public enum FieldKey: String, CaseIterable {
+      case pressure
+      case waterTemperature
+    }
+  }
+
+  public struct Response: Codable, Equatable, Sendable {
+
+    public let feetOfHead: Double
+    public let density: DensityOf<Water>
+    public let warnings: [String]
+
+    public init(feetOfHead: Double, density: DensityOf<Water>, warnings: [String]) {
+      self.feetOfHead = feetOfHead
+      self.density = density
+      self.warnings = warnings
+    }
+  }
+}
+
+// MARK: - Router
+
+public extension SiteRoute.View {
+  enum FeetOfHead: Equatable, Hashable, Sendable {
+    case index
+    case submit(Routes.FeetOfHead.Request)
+
+    static let rootPath = "feet-of-head"
+    typealias Key = Routes.FeetOfHead.Request.FieldKey
+
+    public static let router = OneOf {
+      Route(.case(Self.index)) {
+        Path { rootPath }
+        Method.get
+      }
+      Route(.case(Self.submit)) {
+        Path { rootPath }
+        Method.post
+        Body {
+          FormData {
+            Field(Key.pressure) { Double.parser() }
+            Optionally { Field(Key.waterTemperature) { Double.parser() } }
+          }
+          .map(.memberwise(Routes.FeetOfHead.Request.init))
+        }
+      }
+    }
+  }
+}
+
+#if DEBUG
+  public extension FeetOfHead.Response {
+    static let mock = Self(feetOfHead: 7.95, density: 62.37, warnings: [])
+  }
+#endif

Sources/Routes/Models/HydronicSystemPressure.swift

@@ -2,7 +2,6 @@ import CasePaths
 import PsychrometricClient
 @preconcurrency import URLRouting
 
-//
 public enum HydronicSystemPressure {
 
   public static let description = """

Sources/Routes/SiteRoutes.swift

@@ -104,6 +104,7 @@ public extension SiteRoute {
     case atticVentilation(AtticVentilation)
     case capacitor(Capacitor)
     case dehumidifierSize(DehumidifierSize)
+    case feetOfHead(Self.FeetOfHead)
     case filterPressureDrop(FilterPressureDrop)
     case heatingBalancePoint(HeatingBalancePoint)
     case hvacSystemPerformance(HVACSystemPerformance)
@@ -125,6 +126,9 @@ public extension SiteRoute {
       Route(.case(Self.dehumidifierSize)) {
         DehumidifierSize.router
       }
+      Route(.case(Self.feetOfHead)) {
+        FeetOfHead.router
+      }
       Route(.case(Self.filterPressureDrop)) {
         FilterPressureDrop.router
       }