feat(frontend): adapt delivery form to single root account and credential_available

- Remove mysql_admin_password from CreateMySQLDeliveryPayload;
  the delivery form submits a single root password only
- Wire the task's credential_available boolean into the Catalog
  workbench: sync on create/poll/restore, and hide the one-time
  credential entry once it has been claimed
- Preview mock credential account_host changed from localhost to %

frontend/src/api/delivery.ts

@@ -45,7 +45,6 @@ export interface CreateMySQLDeliveryPayload {
   binlog_expire_logs_seconds?: number
   max_binlog_size?: string
   mysql_root_password?: string
-  mysql_admin_password?: string
 }
 
 export interface DeliveryTask {

frontend/src/views/service/Catalog.vue

@@ -788,6 +788,7 @@ const taskStateLoading = ref(false)
 const credentialRevealed = ref(false)
 const credentialDismissed = ref(false)
 const credentialRevealing = ref(false)
+const credentialAvailable = ref<boolean>()
 const revealedCredentials = ref<DeploymentCredential[]>([])
 const deliveryHistory = ref<DeliveryHistoryItem[]>(loadDeliveryHistory())
 let workbenchReady = false
@@ -912,7 +913,10 @@ const runnerPreview = computed(() => {
   ].join('\n')
 })
 const connectionReady = computed(() => Boolean(deliveredHost.value && deliveredPort.value))
-const credentialEligible = computed(() => connectionReady.value && ['finished', 'register_failed'].includes(lastDeliveryStatus.value))
+const credentialEligible = computed(() => {
+  if (!connectionReady.value || !['finished', 'register_failed'].includes(lastDeliveryStatus.value)) return false
+  return credentialAvailable.value !== false
+})
 const revealedRootCredential = computed(() => revealedCredentials.value.find((item) => item.username === 'root'))
 const resultReady = computed(() => !taskStateLoading.value && !running.value && isTerminalDeliveryStatus(lastDeliveryStatus.value))
 const previewAddress = computed(() => `${selectedHost.value?.ip || 'AWX 自动分配'}:${deliveryForm.port || '自动端口'}`)
@@ -1130,6 +1134,7 @@ async function restoreWorkbench() {
   steps.value = snapshot.steps?.length ? snapshot.steps : defaultSteps()
   credentialRevealed.value = false
   credentialDismissed.value = Boolean(snapshot.deploymentId)
+  credentialAvailable.value = undefined
 
   if (snapshot.deploymentId) {
     taskStateLoading.value = true
@@ -1138,6 +1143,7 @@ async function restoreWorkbench() {
       deliveredHost.value = data.task.target_host_ip || deliveredHost.value
       deliveredPort.value = data.task.mysql_port || deliveredPort.value
       lastDeliveryStatus.value = data.task.status
+      credentialAvailable.value = data.task.credential_available
       deliveryError.value = data.task.error_message || deliveryError.value
       seenEventIds.value = new Set(data.events.map((event) => event.id))
       applyDeliveryStatus(data.task.status, data.task.error_message || '')
@@ -1220,6 +1226,7 @@ function resetExecutionState() {
   deliveryFailed.value = false
   credentialRevealed.value = false
   credentialDismissed.value = false
+  credentialAvailable.value = undefined
   revealedCredentials.value = []
   deliveryError.value = ''
   lastDeliveryStatus.value = ''
@@ -1345,6 +1352,7 @@ async function createTask() {
   try {
     const task = await deliveryApi.createMySQL(mysqlDeliveryPayload(businessLineId))
     deploymentId.value = task.id
+    credentialAvailable.value = task.credential_available
     deliveryForm.rootPassword = ''
     upsertDeliveryHistory(task.id, task.status, task.error_message || '', task.created_at)
     deliveryLog.value += `\n[task] ${task.id} created by ${currentName.value}`
@@ -1402,9 +1410,8 @@ function mysqlDeliveryPayload(businessLineId: number) {
     long_query_time: deliveryForm.longQueryTime,
     binlog_expire_logs_seconds: deliveryForm.binlogExpireSeconds,
     max_binlog_size: deliveryForm.maxBinlogSize,
-    // root 密码以表单为准；后端要求 root/admin 成对传入，平台管理账号密码随机生成
+    // 交付只提供一个允许远程访问的 root 管理员账号。
     mysql_root_password: deliveryForm.rootPassword,
-    mysql_admin_password: generateRootPassword(),
   }
   return payload
 }
@@ -1440,6 +1447,7 @@ async function pollTask(id: string) {
     const data = await deliveryApi.getTask(id)
     deliveredHost.value = data.task.target_host_ip || deliveredHost.value
     deliveredPort.value = data.task.mysql_port || deliveredPort.value
+    credentialAvailable.value = data.task.credential_available
     upsertDeliveryHistory(id, data.task.status, data.task.error_message || '', data.task.created_at)
     applyTaskEvents(data.events)
     applyDeliveryStatus(data.task.status, data.task.error_message || '')
@@ -1533,6 +1541,7 @@ function setupCredentialPreview() {
   deliveredPort.value = 13306
   credentialRevealed.value = false
   credentialDismissed.value = false
+  credentialAvailable.value = true
   revealedCredentials.value = []
   upsertDeliveryHistory(deploymentId.value, 'finished', '', new Date().toISOString())
   if (deliveryHistory.value.length < 3) {
@@ -1679,7 +1688,7 @@ async function revealCredential() {
         host: deliveredHost.value || '10.24.18.21',
         port: deliveredPort.value || 13306,
         username: 'root',
-        account_host: 'localhost',
+        account_host: '%',
         password: deliveryForm.rootPassword,
       }]
     } else {