Derive project device phases from category

src/domain/services/project-device-placement.service.ts

@@ -1,6 +1,7 @@
+import type { CircuitGroupCategory } from "../../shared/constants/circuit-group.js";
+
 export interface ProjectDevicePlacementSource {
-  category?: string | null;
-  phaseType: "single_phase" | "three_phase";
+  category: CircuitGroupCategory;
 }
 
 export interface ProjectDevicePlacementSection {
@@ -14,11 +15,13 @@ export type DefaultCircuitSectionKey = "lighting" | "single_phase" | "three_phas
 export function inferProjectDeviceSectionKey(
   device: ProjectDevicePlacementSource
 ): DefaultCircuitSectionKey {
-  const category = (device.category ?? "").trim().toLowerCase();
-  if (category.includes("light") || category.includes("beleuchtung")) {
-    return "lighting";
-  }
-  return device.phaseType;
+  return device.category;
+}
+
+export function resolveProjectDevicePhaseType(
+  category: CircuitGroupCategory
+): "single_phase" | "three_phase" {
+  return category === "three_phase" ? "three_phase" : "single_phase";
 }
 
 export function isProjectDevicePlacementValid(