feat(chat): add private message unlock flow

src/stores/chat/chat-machine.helpers.ts

@@ -49,17 +49,25 @@ export const chatRepo: IChatRepository = chatRepository;
  */
 export function localMessagesToUi(
   records: ReadonlyArray<{
+    id?: string;
     content: string;
     role: string;
     createdAt: string;
     imageUrl?: string | null;
+    isPrivate?: boolean | null;
+    privateLocked?: boolean | null;
+    privateHint?: string | null;
   }>,
 ): UiMessage[] {
   return records.map((m) => ({
+    ...(m.id ? { id: m.id } : {}),
     content: m.content,
     isFromAI: m.role === "assistant",
     date: messageDateFromCreatedAt(m.createdAt),
     ...(m.imageUrl ? { imageUrl: m.imageUrl } : {}),
+    ...(m.isPrivate != null ? { isPrivate: m.isPrivate } : {}),
+    ...(m.privateLocked != null ? { privateLocked: m.privateLocked } : {}),
+    ...(m.privateHint != null ? { privateHint: m.privateHint } : {}),
   }));
 }
 
@@ -76,6 +84,7 @@ function messageDateFromCreatedAt(createdAt: string): string {
  */
 export function sendResponseToUiMessage(response: ChatSendResponse): UiMessage {
   return {
+    ...(response.messageId ? { id: response.messageId } : {}),
     content: response.reply,
     isFromAI: true,
     date: todayString(new Date(response.timestamp)),