refactor: remove Subject field from Conversation model and related logic, replace with CustomerName

web/app/dashboard/tickets/_components/create-ticket-from-conversation-dialog.tsx

@@ -7,7 +7,7 @@ import { EditDialog } from "./edit"
 
 type ConversationSeed = {
   id: number
-  subject: string
+  customerName: string
   customerId?: number
   lastMessageSummary?: string
   currentAssigneeId?: number
@@ -28,7 +28,7 @@ export function CreateTicketFromConversationDialog({
 }: CreateTicketFromConversationDialogProps) {
   const initialValues = conversation
     ? {
-        title: conversation.subject || "",
+        title: conversation.customerName || "",
         description: conversation.lastMessageSummary || "",
         priority: 2,
         severity: 1,

web/app/dashboard/tickets/detail/page.tsx

@@ -880,7 +880,7 @@ export default function TicketDetailPage() {
                       {sourceConversation ? (
                         <SurfacePanel className="p-2.5">
                           <div className="text-sm font-medium">
-                            {sourceConversation.subject || "未命名会话"}
+                            {sourceConversation.customerName || "未命名客户"}
                           </div>
                           <div className="mt-2 flex flex-wrap gap-2 text-xs text-muted-foreground">
                             <span>