rounded-0 sur le card du collectionTree.

src/components/CollectionsTree.vue

 <template>
-  <v-card flat>
+  <v-card flat class="rounded-0">
     <v-toolbar :elevation="0" dark class="rounded-0 ma-0 pa-0">
       <v-toolbar-title class="d-flex">
         <v-btn text @click="loadHome()">
@@ -17,7 +17,7 @@
         hoverable
         activatable
         item-text="title"
-        class="jama-collection-tree"
+        class="jama-collection-tree rounded-0"
         @update:active="updateActive"
         return-object
     >