feat working on vendor views.

Sources/DatabaseClientLive/Vendors.swift

@@ -37,13 +37,20 @@ public extension DatabaseClient.Vendors {
         query = query.with(\.$branches)
       }
       return try await query.first().map { try $0.toDTO(includeBranches: withBranches) }
-    } update: { id, updates in
+    } update: { id, updates, withBranches in
       guard let model = try await VendorModel.find(id, on: db) else {
         throw NotFoundError()
       }
       try model.applyUpdates(updates)
       try await model.save(on: db)
-      return try model.toDTO()
+      if withBranches != .withBranches {
+        return try model.toDTO()
+      }
+      return try await VendorModel.query(on: db)
+        .filter(\.$id == id)
+        .with(\.$branches)
+        .first()!
+        .toDTO()
     }
   }
 }