feat(sync): trust Hiboutik answers for deletions

A successful (2xx) answer from Hiboutik is now the truth, even an empty
list: records missing from it are deleted. The "empty list means API
issue" safety nets are removed.

Deletion stays safe because a failed call deletes nothing: HTTP errors
throw, and the new HiboutikClient.getList (used by getAllPages and the
non-paginated lists) also throws on a 2xx body that is not a list, so a
malformed answer is never mistaken for an empty list. A 2xx without body
is an empty list.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/services/hiboutik/brand.hiboutik.service.ts

@@ -25,11 +25,7 @@ export class BrandHiboutikService {
       (brand) => `Hiboutik brand ${brand.hiboutikId}`,
     );
 
-    // Safety net: an empty answer from Hiboutik most likely means an API issue
-    if (hiboutikBrands.length === 0) {
-      this.logger.warn('Hiboutik returned no brands: deletion skipped.');
-      return;
-    }
+    // Hiboutik is trusted: a successful (2xx) answer, even an empty list, is the truth. An HTTP error throws before this point.
     const nbDeleted = await this.brandDatabaseRepository.deleteMissing(hiboutikBrands.map((dto) => Number(dto.brand_id)));
     this.logger.log(
       `Brands sync ended: ${hiboutikBrands.length - nbFailed}/${hiboutikBrands.length} synced, ${nbFailed} failed, ${nbDeleted} deleted.`,