fix(pl24): Volvo subgroup drilling via vin-group.action HTML

Volvo's VIN catalog is a 3-level vin-group.action?group1=…[&group2=…] HTML
tree; PL24's json-vin-*-group.action JSON endpoints now 404. Add HTML
subgroup extraction (keep links one group-level deeper than the current
path) in ford-legacy fetchSubGroupsByPath, and route vin-group.action?group1=
nodes through getChildren (drill-first, fall back to parts) in
getCategoryWithParts. Recovers Volvo group1→group2 navigation. Leaf parts
handled separately.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

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

@@ -895,6 +895,34 @@ export class CategoriesService {
         : { ...base, loadError: true };
     }
 
+    // Volvo VIN-indexed catalog: vin-group.action?group1=…[&group2=…] nodes are
+    // parents whose subgroups live in the same HTML (PL24's old JSON
+    // json-vin-main-group.action path now 404s). They carry no link_wid, so the
+    // group-node branch above misses them. Drill: if subgroups come back it's a
+    // parent; if none, fall through to the leaf parts path (the deepest group
+    // level carries an image-board + parts).
+    if (
+      category.source === "pl24" &&
+      category.linkPath?.includes("vin-group.action") &&
+      category.linkPath?.includes("group1=") &&
+      category.vehicleId
+    ) {
+      const volvoChildren = await this.getChildren(categoryId);
+      if (volvoChildren.length > 0) {
+        return {
+          id: category.id,
+          name: category.name,
+          description: category.nameOriginal || null,
+          parentId: category.parentId || null,
+          parts: [],
+          schemaPics: [],
+          hotspots: [],
+          children: volvoChildren,
+        };
+      }
+      // No subgroups → leaf; fall through to the parts path below.
+    }
+
     // Leaf category — get or fetch parts
     let loadError = false;
     let discoveredChildren: any[] = [];
@@ -996,7 +1024,11 @@ export class CategoriesService {
               }));
 
               if (allParts.length > 0) {
-                dbParts = await this.db.insert(parts).values(allParts).returning();
+                dbParts = await this.db
+                  .insert(parts)
+                  .values(allParts)
+                  .onConflictDoNothing()
+                  .returning();
                 this.logger.log(
                   `Stored ${dbParts.length} PartsCatalogs parts for category ${categoryId}`,
                 );
@@ -1146,7 +1178,11 @@ export class CategoriesService {
               };
             });
 
-            dbParts = await this.db.insert(parts).values(insertData).returning();
+            dbParts = await this.db
+              .insert(parts)
+              .values(insertData)
+              .onConflictDoNothing()
+              .returning();
             this.logger.log(`Stored ${dbParts.length} EMEX parts for category ${categoryId}`);
           }
 
@@ -1242,7 +1278,11 @@ export class CategoriesService {
                 source: "pl24" as const,
               }));
 
-              dbParts = await this.db.insert(parts).values(insertData).returning();
+              dbParts = await this.db
+                .insert(parts)
+                .values(insertData)
+                .onConflictDoNothing()
+                .returning();
             }
 
             // Store schema image if available