feat(files): POSIX paths, elevation, recursive chmod, access hints and docs

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/pages/ServersPage.vue

@@ -184,6 +184,17 @@
           <v-text-field v-model="form.ssh_user" label="SSH 用户" variant="outlined" density="compact" class="mb-2" :rules="[required('用户名')]" />
           <v-text-field v-model="form.ssh_port" label="SSH 端口" variant="outlined" density="compact" type="number" class="mb-2" />
           <v-text-field v-model="form.password" label="密码" variant="outlined" density="compact" type="password" class="mb-2" />
+          <v-select
+            v-model="form.files_elevation"
+            :items="filesElevationItems"
+            item-title="title"
+            item-value="value"
+            label="文件管理提权"
+            variant="outlined"
+            density="compact"
+            hint="非 root SSH 用户需目标机配置免密 sudo；示例见 docs/deploy/nexus-files-sudoers.example"
+            persistent-hint
+          />
         </v-card-text>
         <v-card-actions>
           <v-spacer />
@@ -271,9 +282,16 @@ const deleting = ref(false)
 const deletingServer = ref<ServerApiItem | null>(null)
 const editingId = ref<number | null>(null)
 
+const filesElevationItems = [
+  { title: '自动（权限失败时 sudo）', value: 'auto_sudo' },
+  { title: '关闭 sudo', value: 'off' },
+  { title: '始终 sudo（排障）', value: 'always_sudo' },
+]
+
 const form = ref({
   name: '', address: '', category: '', platform_id: null as number | null,
   ssh_user: '', ssh_port: 22, password: '',
+  files_elevation: 'auto_sudo' as 'off' | 'auto_sudo' | 'always_sudo',
 })
 
 // ── Batch selection (Vuetify returns IDs when item-value="id", objects when return-object) ──
@@ -463,6 +481,7 @@ function editServer(item: ServerApiItem) {
     name: item.name, address: item.domain || '', category: item.category || '',
     platform_id: item.platform_id, ssh_user: item.username || '',
     ssh_port: item.port || 22, password: '',
+    files_elevation: item.files_elevation || 'auto_sudo',
   }
   showAdd.value = true
 }
@@ -483,6 +502,7 @@ async function saveServer() {
       category: form.value.category || undefined,
       platform_id: form.value.platform_id || undefined,
       password: form.value.password || undefined,
+      files_elevation: form.value.files_elevation,
     }
     if (editing.value && editingId.value) {
       await http.put(`/servers/${editingId.value}`, payload)
@@ -520,7 +540,10 @@ async function doDelete() {
 function resetForm() {
   editing.value = false
   editingId.value = null
-  form.value = { name: '', address: '', category: '', platform_id: null, ssh_user: '', ssh_port: 22, password: '' }
+  form.value = {
+    name: '', address: '', category: '', platform_id: null, ssh_user: '', ssh_port: 22,
+    password: '', files_elevation: 'auto_sudo',
+  }
 }
 
 // ── Init ──