fix(categories): broaden leaf detection to all /extern/*/{vin,mdl}_items endpoints

The leaf-path checks only matched /servicepart/vin_items literally, but
PL24's P5 modern catalog ships the same shape under /chemicals/vin_items,
/accessories/vin_items, /chemicals/mdl_items, etc. When user clicked a
"Rötuşkalemseti" (touch-up paint set) category whose linkPath was
/p5vwag/extern/chemicals/vin_items, the code drilled in, treated each
paint chemical's per-part URL (?partno=LLSMAX010) as a sub-category,
and inserted 228 ghost rows under it. Replace the literal substring
match with a regex that covers the whole /extern/{kind}/(vin|mdl)_items
pattern; apply to both the user-vehicle (categories.service) and the
catalog (catalog.service) flows.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/api/src/catalog/catalog.service.ts

@@ -1190,8 +1190,12 @@ export class CatalogService {
       lower.includes("/bom/") ||
       lower.includes("/bomdetails") ||
       lower.includes("/partinfo/") ||
-      lower.includes("/servicepart/vin_items") ||
-      lower.includes("image-board.action") // PSA illustration leaf
+      // PL24 P5 leaf items endpoints — chemicals, servicepart, accessories,
+      // any /extern/<kind>/(vin|mdl)_items combination. These return parts,
+      // not subgroups, so they must short-circuit drill-down.
+      /\/extern\/[^/]+\/(vin_items|mdl_items)\b/.test(lower) ||
+      lower.includes("image-board.action") || // PSA illustration leaf
+      lower.includes("json-vin-bom-detail.action")
     );
   }
 

apps/api/src/categories/categories.service.ts

@@ -517,20 +517,17 @@ export class CategoriesService {
       return [];
     }
 
-    // BOM / servicepart item links are leaf categories — they return parts, not subgroups
+    // BOM / *_items / partinfo / image-board pages all return PARTS, not
+    // subgroups. Drilling into them used to insert per-part endpoints as
+    // ghost child categories — keep the regex wide so any /extern/{kind}/
+    // (vin|mdl)_items endpoint is recognised, not just /servicepart/.
     const lp = linkPath.toLowerCase();
     if (
       lp.includes("/bom/") ||
       lp.includes("/bomdetails") ||
       lp.includes("/partinfo/") ||
-      lp.includes("/servicepart/vin_items") ||
-      // PSA / Hyundai / Opel / Volvo image-board pages and the Ford VIN
-      // vin-image-board.action equivalent. Drilling into them yields BOM rows,
-      // not sub-groups — let getCategoryWithParts handle those as parts.
+      /\/extern\/[^/]+\/(vin_items|mdl_items)\b/.test(lp) ||
       lp.includes("image-board.action") ||
-      // json-vin-bom-detail.action is the per-part endpoint (one level past a
-      // leaf). If any code ever inserts it as a category linkPath, treat the
-      // node as a dead-end leaf so the UI doesn't loop into it.
       lp.includes("json-vin-bom-detail.action")
     ) {
       return [];
@@ -1178,11 +1175,17 @@ export class CategoriesService {
           ? !!c.linkPath && dbChildCount === 0
           : c.source === "parts-catalogs"
             ? !!c.linkPath?.startsWith("pcat:") && dbChildCount === 0
-            : c.linkPath?.toLowerCase()?.includes("/bom/") ||
-              c.linkPath?.toLowerCase()?.includes("/bomdetails") ||
-              c.linkPath?.toLowerCase()?.includes("/partinfo/") ||
-              c.linkPath?.toLowerCase()?.includes("/servicepart/vin_items") ||
-              (!c.linkPath && dbChildCount === 0);
+            : (() => {
+                const lp = c.linkPath?.toLowerCase() ?? "";
+                return (
+                  lp.includes("/bom/") ||
+                  lp.includes("/bomdetails") ||
+                  lp.includes("/partinfo/") ||
+                  /\/extern\/[^/]+\/(vin_items|mdl_items)\b/.test(lp) ||
+                  lp.includes("image-board.action") ||
+                  (!c.linkPath && dbChildCount === 0)
+                );
+              })();
       return {
         ...c,
         schemaImageUrl: picMap.get(c.id) || null,