feat(frontend) : allow multiple type selection in time entry drawer and remove group creation from kanban

Replace single-select dropdown with multi-select colored badges for types in TimeEntryDrawer, matching TaskDrawer pattern. Remove the "Ajouter un groupe" button and associated code from the kanban page.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/pages/projects/[id]/index.vue

@@ -2,20 +2,12 @@
     <div>
         <div class="flex items-center justify-between">
             <h1 class="text-2xl font-bold text-primary-500">{{ project?.name ?? '' }}</h1>
-            <div class="flex gap-3">
-                <button
-                    class="rounded-md bg-secondary-500 px-4 py-2 text-sm font-semibold text-white hover:bg-secondary-600"
-                    @click="openGroupCreate"
-                >
-                    + Ajouter un groupe
-                </button>
-                <button
-                    class="rounded-md bg-primary-500 px-4 py-2 text-sm font-semibold text-white hover:bg-secondary-500"
-                    @click="openTaskCreate"
-                >
-                    + Ajouter un ticket
-                </button>
-            </div>
+            <button
+                class="rounded-md bg-primary-500 px-4 py-2 text-sm font-semibold text-white hover:bg-secondary-500"
+                @click="openTaskCreate"
+            >
+                + Ajouter un ticket
+            </button>
         </div>
 
         <div class="mt-4">
@@ -137,12 +129,6 @@
             @saved="onSaved"
         />
 
-        <TaskGroupDrawer
-            v-model="groupDrawerOpen"
-            :group="selectedGroup"
-            :project-id="projectId"
-            @saved="onSaved"
-        />
     </div>
 </template>
 
@@ -193,8 +179,6 @@ const dragOverStatusId = ref<number | null>(null)
 const dragCounter = ref(0)
 const taskDrawerOpen = ref(false)
 const selectedTask = ref<Task | null>(null)
-const groupDrawerOpen = ref(false)
-const selectedGroup = ref<TaskGroup | null>(null)
 
 const groupFilterOptions = computed(() =>
     groups.value.map(g => ({ label: g.title, value: g.id }))
@@ -249,11 +233,6 @@ function openTaskEdit(task: Task) {
     taskDrawerOpen.value = true
 }
 
-function openGroupCreate() {
-    selectedGroup.value = null
-    groupDrawerOpen.value = true
-}
-
 function onDragEnter(id: number) {
     dragCounter.value++
     dragOverStatusId.value = id