feat(comments): 软删占位、理由与恢复，管理删仅对访客打码

自删/管理删差异文案与理由可见性，评论者与管理员免马赛克，并支持恢复与处理人链接。

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

frontend/lib/api.ts

@@ -315,6 +315,18 @@ export interface Comment {
   user: User;
   /** 软删占位 */
   deleted?: boolean;
+  /** 管理删除（DeletedBy≠评论者） */
+  staff_deleted?: boolean;
+  delete_type?: string;
+  delete_reason?: string;
+  deleted_by?: number;
+  /** 管理删执行者（公开，用于主页快捷入口） */
+  deleted_by_user?: {
+    id: number;
+    username: string;
+    nickname: string;
+    avatar: string;
+  };
 }
 
 // 评论树节点：主评论为根，replies 为其全部子回复（时间正序，全量 SSR 直出）
@@ -1105,9 +1117,26 @@ export async function apiToggleLike(postId: string) {
   return res.json();
 }
 
-export async function apiDeleteComment(postId: string, commentId: number) {
+export async function apiDeleteComment(
+  postId: string,
+  commentId: number,
+  opts: { delete_type?: string; delete_reason: string }
+) {
   const res = await fetchWithRefresh(`/api/posts/${postId}/comments/${commentId}`, {
     method: "DELETE",
+    headers: clientHeaders({ "Content-Type": "application/json" }),
+    body: JSON.stringify({
+      delete_type: opts.delete_type || "",
+      delete_reason: opts.delete_reason || "",
+    }),
+  });
+  return res.json();
+}
+
+/** 恢复软删评论（自删作者或版主） */
+export async function apiRestoreComment(postId: string, commentId: number) {
+  const res = await fetchWithRefresh(`/api/posts/${postId}/comments/${commentId}/restore`, {
+    method: "PUT",
     headers: clientHeaders(),
   });
   return res.json();
@@ -1735,8 +1764,10 @@ export const apiAdminRestorePost = (id: number) =>
   contentAction(`/api/admin/content/posts/${id}/restore`, "PUT");
 export const apiAdminPurgePost = (id: number) =>
   contentAction(`/api/admin/content/posts/${id}/purge`, "DELETE");
-export const apiAdminSoftDeleteComment = (id: number) =>
-  contentAction(`/api/admin/content/comments/${id}`, "DELETE");
+export const apiAdminSoftDeleteComment = (
+  id: number,
+  opts: { delete_type: string; delete_reason: string }
+) => contentAction(`/api/admin/content/comments/${id}`, "DELETE", opts);
 export const apiAdminRestoreComment = (id: number) =>
   contentAction(`/api/admin/content/comments/${id}/restore`, "PUT");
 export const apiAdminPurgeComment = (id: number) =>