fix(workflow) : couleurs par defaut par categorie + migration de correction du workflow Standard

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

frontend/components/admin/WorkflowDrawer.vue

@@ -95,6 +95,7 @@
 
 <script setup lang="ts">
 import type { Workflow, StatusCategory } from '~/services/dto/workflow'
+import { STATUS_CATEGORY_COLOR } from '~/services/dto/workflow'
 import type { TaskStatusWrite } from '~/services/dto/task-status'
 import { useWorkflowService } from '~/services/workflows'
 import { useTaskStatusService } from '~/services/task-statuses'
@@ -169,10 +170,20 @@ watch(() => props.modelValue, (open) => {
     touched.name = false
 })
 
+watch(() => form.statuses.map(s => s.category), (cats, prev) => {
+    if (!prev) return
+    cats.forEach((cat, i) => {
+        const s = form.statuses[i]
+        if (s && cat !== prev[i] && s.color === STATUS_CATEGORY_COLOR[prev[i] as StatusCategory]) {
+            s.color = STATUS_CATEGORY_COLOR[cat as StatusCategory]
+        }
+    })
+})
+
 function addStatus() {
     form.statuses.push({
         label: '',
-        color: '#222783',
+        color: STATUS_CATEGORY_COLOR.todo,
         position: form.statuses.length,
         isFinal: false,
         category: 'todo',