fix: role code auto-gen; fix permission tree API response parsing; fix buildPermTree parent_id=0

frontend/src/views/system/roles/index.vue

@@ -29,11 +29,11 @@ const form = reactive({
 })
 
 const formRules = {
-  name: [{ required: true, message: '请输入角色名称', trigger: 'blur' }],
-  code: [
-    { required: true, message: '请输入角色标识', trigger: 'blur' },
-    { pattern: /^[a-zA-Z][a-zA-Z0-9_:]*$/, message: '只允许字母、数字、下划线，以字母开头', trigger: 'blur' }
-  ]
+  name: [{ required: true, message: '请输入角色名称', trigger: 'blur' }]
+}
+
+function genCode() {
+  return 'role_' + Date.now().toString(36)
 }
 
 // ─── Permission assignment ────────────────────────────────────────────────────
@@ -68,17 +68,23 @@ async function fetchList() {
 
 async function fetchPermTree() {
   try {
-    const res = await permissionApi.getList({ per_page: 500 })
-    const flat = res.data?.list || res.data?.data || []
-    permTree.value = buildPermTree(flat)
+    const res = await permissionApi.getList({ page_size: 500 })
+    // API returns already-tree-structured array in res.data
+    const data = res.data
+    if (Array.isArray(data)) {
+      permTree.value = data
+    } else {
+      const flat = data?.list || data?.data || []
+      permTree.value = buildPermTree(flat)
+    }
   } catch {
     //
   }
 }
 
-function buildPermTree(nodes, parentId = null) {
+function buildPermTree(nodes, parentId = 0) {
   return nodes
-    .filter(n => (n.parent_id ?? null) === parentId)
+    .filter(n => (n.parent_id ?? 0) === parentId)
     .map(n => ({ ...n, children: buildPermTree(nodes, n.id) }))
 }
 
@@ -97,7 +103,7 @@ function handleReset() {
 function handleAdd() {
   isEdit.value = false
   dialogTitle.value = '新增角色'
-  Object.assign(form, { id: null, name: '', code: '', description: '', status: 1 })
+  Object.assign(form, { id: null, name: '', code: genCode(), description: '', status: 1 })
   dialogVisible.value = true
 }
 
@@ -274,9 +280,9 @@ onMounted(() => {
         <el-form-item label="角色名称" prop="name">
           <el-input v-model="form.name" placeholder="请输入角色名称" />
         </el-form-item>
-        <el-form-item label="角色标识" prop="code">
-          <el-input v-model="form.code" placeholder="如: admin, nurse_manager" :disabled="isEdit" />
-          <div class="form-tip">标识用于程序内部权限判断，创建后不可修改</div>
+        <el-form-item v-if="isEdit" label="角色标识">
+          <el-input v-model="form.code" disabled />
+          <div class="form-tip">角色标识由系统自动生成，不可修改</div>
         </el-form-item>
         <el-form-item label="描述" prop="description">
           <el-input