Add for leave family

apps/frontend/lib/api.ts

@@ -859,6 +859,7 @@ export interface ChatRoomMember {
   pinnedAt?: string;
   familyRole?: string;
   isChatCreator?: boolean;
+  inFamily?: boolean;
 }
 
 export interface ChatRoom {
@@ -874,6 +875,7 @@ export interface ChatRoom {
   updatedAt: string;
   isPinned?: boolean;
   pinnedAt?: string;
+  peerLeftFamily?: boolean;
   members: ChatRoomMember[];
   lastMessage?: ChatMessage;
 }
@@ -978,6 +980,17 @@ export async function removeFamilyMember(memberId: string, token?: string | null
   return apiFetch<{ count: number }>(`/family/members/${memberId}`, { method: 'DELETE' }, token);
 }
 
+export async function leaveFamilyGroup(groupId: string, token?: string | null, newOwnerUserId?: string) {
+  return apiFetch<{ count: number; deleted?: boolean }>(
+    `/family/groups/${groupId}/leave`,
+    {
+      method: 'POST',
+      body: JSON.stringify(newOwnerUserId ? { newOwnerUserId } : {})
+    },
+    token
+  );
+}
+
 export async function fetchChatMessages(roomId: string, token?: string | null, beforeMessageId?: string) {
   const query = beforeMessageId ? `?beforeMessageId=${beforeMessageId}` : '';
   return apiFetch<{ messages?: ChatMessage[] }>(`/chat/rooms/${roomId}/messages${query}`, {}, token);