feat(settings): 站点界面动画总开关与子开关

管理后台可关全站动画，并细调代码折叠、平滑滚动、装饰入场；统一 lib/motion，尊重系统减少动态效果。

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

frontend/lib/api.ts

@@ -552,6 +552,14 @@ export interface PublicSettings {
   code_block_auto_fold: boolean;
   /** 折叠阈值行数（超过则折叠；0=无预览）；缺省 5 */
   code_block_fold_lines: number;
+  /** 界面动画总开关；缺省 true */
+  ui_animations: boolean;
+  /** 代码折叠动画子开关；缺省 true */
+  anim_code_fold: boolean;
+  /** 平滑滚动子开关；缺省 true */
+  anim_smooth_scroll: boolean;
+  /** 装饰入场子开关；缺省 true */
+  anim_chrome: boolean;
 }
 
 const DEFAULT_PUBLIC_SETTINGS: PublicSettings = {
@@ -563,6 +571,10 @@ const DEFAULT_PUBLIC_SETTINGS: PublicSettings = {
   post_cooldown_hours: 24,
   code_block_auto_fold: true,
   code_block_fold_lines: 5,
+  ui_animations: true,
+  anim_code_fold: true,
+  anim_smooth_scroll: true,
+  anim_chrome: true,
 };
 
 function normalizePublicSettings(data: Partial<PublicSettings> | null | undefined): PublicSettings {
@@ -586,6 +598,10 @@ function normalizePublicSettings(data: Partial<PublicSettings> | null | undefine
       data.code_block_fold_lines <= 100
         ? Math.round(data.code_block_fold_lines)
         : DEFAULT_PUBLIC_SETTINGS.code_block_fold_lines,
+    ui_animations: data?.ui_animations !== false,
+    anim_code_fold: data?.anim_code_fold !== false,
+    anim_smooth_scroll: data?.anim_smooth_scroll !== false,
+    anim_chrome: data?.anim_chrome !== false,
   };
 }
 
@@ -931,10 +947,30 @@ export async function apiDrawLottery(postId: string) {
   return res.json();
 }
 
-export async function apiDeletePost(postId: string) {
+/** 管理删帖类型（与后端 model.PostDeleteType* 一致） */
+export const POST_DELETE_TYPES = [
+  { value: "spam", label: "垃圾广告" },
+  { value: "violation", label: "违规内容" },
+  { value: "off_topic", label: "灌水跑题" },
+  { value: "duplicate", label: "重复内容" },
+  { value: "other", label: "其他" },
+] as const;
+
+export function postDeleteTypeLabel(t?: string): string {
+  return POST_DELETE_TYPES.find((x) => x.value === t)?.label || t || "";
+}
+
+export async function apiDeletePost(
+  postId: string,
+  opts?: { delete_type?: string; delete_reason?: string }
+) {
   const res = await fetchWithRefresh(`/api/posts/${postId}`, {
     method: "DELETE",
-    headers: clientHeaders(),
+    headers: clientHeaders({ "Content-Type": "application/json" }),
+    body: JSON.stringify({
+      delete_type: opts?.delete_type || "",
+      delete_reason: opts?.delete_reason || "",
+    }),
   });
   return res.json();
 }
@@ -1073,6 +1109,15 @@ export async function apiDeleteComment(postId: string, commentId: number) {
   return res.json();
 }
 
+/** 版主硬删评论及子树（不占位） */
+export async function apiPurgeComment(postId: string, commentId: number) {
+  const res = await fetchWithRefresh(`/api/posts/${postId}/comments/${commentId}/purge`, {
+    method: "DELETE",
+    headers: clientHeaders(),
+  });
+  return res.json();
+}
+
 // ===== 通知 =====
 
 export async function apiFetchNotifications(page = 1): Promise<NotificationsResponse> {
@@ -1488,6 +1533,10 @@ export type UpdateSiteSettingsBody = {
   post_cooldown_hours?: number;
   code_block_auto_fold?: boolean;
   code_block_fold_lines?: number;
+  ui_animations?: boolean;
+  anim_code_fold?: boolean;
+  anim_smooth_scroll?: boolean;
+  anim_chrome?: boolean;
 };
 
 // 更新站点设置（字段可选）；accent 传空串恢复默认主题色
@@ -1657,16 +1706,26 @@ export async function apiAdminContentComments(
   return data;
 }
 
-async function contentAction(url: string, method: string): Promise<void> {
-  const res = await fetchWithRefresh(url, { method, headers: clientHeaders() });
+async function contentAction(
+  url: string,
+  method: string,
+  body?: Record<string, unknown>
+): Promise<void> {
+  const res = await fetchWithRefresh(url, {
+    method,
+    headers: clientHeaders(body ? { "Content-Type": "application/json" } : undefined),
+    body: body ? JSON.stringify(body) : undefined,
+  });
   if (!res.ok) {
     const data = await res.json().catch(() => ({}));
     throw new Error(data.error || "操作失败");
   }
 }
 
-export const apiAdminSoftDeletePost = (id: number) =>
-  contentAction(`/api/admin/content/posts/${id}`, "DELETE");
+export const apiAdminSoftDeletePost = (
+  id: number,
+  opts: { delete_type: string; delete_reason: string }
+) => contentAction(`/api/admin/content/posts/${id}`, "DELETE", opts);
 export const apiAdminRestorePost = (id: number) =>
   contentAction(`/api/admin/content/posts/${id}/restore`, "PUT");
 export const apiAdminPurgePost = (id: number) =>