fix(channel-conversation): address code review issues for Task 5

- Make frontend account filter case-insensitive in Conversation.vue
- Warn when bind dialog is submitted without selecting an account
- Reuse AccountSelector.isHealthy in resolvePersonTarget
- Expand ConversationService.bindAccount unit tests
- Update channel mismatch assertion in SendServiceResolveTargetTest
- Move currentConversationId declaration near tag binding state

admin-web/src/views/Conversation.vue

@@ -220,7 +220,9 @@ function formatAccountName(id: number | undefined) {
 const filteredBindAccounts = computed(() => {
   const channelType = currentBindConversation.value?.channelType
   if (!channelType) return accounts.value
-  return accounts.value.filter((a: any) => a.channelType === channelType)
+  return accounts.value.filter((a: any) =>
+    a.channelType?.toLowerCase() === channelType?.toLowerCase()
+  )
 })
 
 function formatConversationType(type: number | undefined) {
@@ -337,7 +339,10 @@ function openBindAccount(row: any) {
 }
 
 async function handleBindAccount() {
-  if (!bindAccountForm.accountId || !currentBindConversation.value) return
+  if (!bindAccountForm.accountId || !currentBindConversation.value) {
+    ElMessage.warning('请选择账号')
+    return
+  }
   try {
     await bindConversationAccount(currentBindConversation.value.id, bindAccountForm)
     ElMessage.success('绑定成功')
@@ -348,8 +353,8 @@ async function handleBindAccount() {
   }
 }
 
-const currentConversationId = ref<number | undefined>()
 
+const currentConversationId = ref<number | undefined>()
 const bindTagsVisible = ref(false)
 const bindTagsForm = reactive({
   tagIds: [] as number[],