fixed builder hydration issues

components/parts/PartsBrowseClient.tsx

@@ -21,7 +21,7 @@ import Pagination from "@/components/parts/Pagination";
 import PlatformSwitcher from "@/components/parts/PlatformSwitcher";
 import { normalizePlatformKey } from "@/lib/platforms";
 import type { UiPart } from "@/types/uiPart";
-import type { Category } from "@/types/builderSlots";
+import type { BuilderSlotKey, Category } from "@/types/builderSlots";
 import {
   PART_ROLE_TO_CATEGORY,
   normalizePartRole,
@@ -310,15 +310,17 @@ export default function PartsBrowseClient(props: {
   // Add → Builder handoff
   // ----------------------------
   const handleAddToBuild = (p: UiPart) => {
-    const normalizedRole = normalizePartRole(partRole);
-    const categoryId: Category | null =
+    // Always normalize first; our mappings may alias multiple roles to one canonical builder category
+    const roleKey = normalizePartRole(partRole);
+
+    const categoryId: BuilderSlotKey | null =
+      PART_ROLE_TO_CATEGORY[roleKey] ??
       PART_ROLE_TO_CATEGORY[partRole] ??
-      PART_ROLE_TO_CATEGORY[normalizedRole] ??
       null;
 
     if (!categoryId) {
       alert(
-        `No Category mapping found for role "${partRole}". Add it to catalogMappings.`
+        `No Category mapping found for role "${partRole}" (normalized: "${roleKey}"). Add it to catalogMappings.`
       );
       return;
     }