feat(posts): 类型帖截止时间、抽奖奖品表与悬赏发帖体验

统一投票/悬赏/抽奖截止与状态展示，抽奖支持多奖品行；发帖页悬赏积分对齐表格输入，并在余额不足时于底部就地提示。

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/lib/api.ts

@@ -254,6 +254,7 @@ export interface QuestionState {
   accepted_comment_id: number;
   accepted_floor: number;
   accepted_answer?: AcceptedAnswer | null;
+  solved_at?: string;
   can_accept: boolean;
   can_solve: boolean;
   can_reopen: boolean;
@@ -279,6 +280,8 @@ export interface PollState {
   multi: boolean;
   closed: boolean;
   anonymous: boolean;
+  ends_at?: string;
+  closed_at?: string;
   total_votes: number;
   voters: number;
   my_options: number[];
@@ -298,7 +301,11 @@ export interface BountyState {
   ends_at?: string;
   settled: boolean;
   can_accept: boolean;
-  can_refund: boolean;
+}
+
+export interface LotteryPrize {
+  name: string;
+  count: number;
 }
 
 export interface LotteryEntrant {
@@ -309,17 +316,21 @@ export interface LotteryEntrant {
   /** 中奖楼层评论 ID（该用户最早主评，每人仅一条） */
   comment_id?: number;
   floor?: number;
+  prize_name?: string;
 }
 
 export interface LotteryState {
   slots: number;
+  prizes: LotteryPrize[];
   drawn: boolean;
   closed: boolean;
   ends_at?: string;
   entry_count: number;
   eligible?: boolean;
+  /** 新号入池冷静期小时数（与发帖冷静期同源，0=关闭） */
+  cooldown_hours?: number;
   can_draw: boolean;
-  can_close: boolean;
+  can_edit_prizes?: boolean;
   winners: LotteryEntrant[];
 }
 
@@ -938,14 +949,6 @@ export async function apiAcceptBounty(postId: string, commentId: number) {
   return res.json();
 }
 
-export async function apiRefundBounty(postId: string) {
-  const res = await fetchWithRefresh(`/api/posts/${postId}/bounty/refund`, {
-    method: "POST",
-    headers: clientHeaders(),
-  });
-  return res.json();
-}
-
 export async function apiAcceptQuestion(postId: string, commentId: number) {
   const res = await fetchWithRefresh(`/api/posts/${postId}/question/accept`, {
     method: "POST",
@@ -971,14 +974,6 @@ export async function apiReopenQuestion(postId: string) {
   return res.json();
 }
 
-export async function apiCloseLottery(postId: string) {
-  const res = await fetchWithRefresh(`/api/posts/${postId}/lottery/close`, {
-    method: "POST",
-    headers: clientHeaders(),
-  });
-  return res.json();
-}
-
 export async function apiDrawLottery(postId: string) {
   const res = await fetchWithRefresh(`/api/posts/${postId}/lottery/draw`, {
     method: "POST",