fix(react): address Doctor findings (#1143)

Accessibility/semantics pass aligned with React Doctor: role-based spans/divs become real buttons, role=status becomes <output>, modals use native <dialog>, author/peer flags render as <img>, and embed/challenge iframes are sandboxed. Includes review follow-ups: correct button chrome/centering/themed dialog colors and focus rings, the missing aria-label i18n keys (all languages), the Yandex image-search URL, clearer .bso setup steps, a keyboard-accessible image-search dropdown, and removal of the post-edit ('comment edited') display (mod edits unchanged).

public/translations/zh/default.json

@@ -144,10 +144,6 @@
   "show_worksafe_boards_only": "仅显示安全工作板",
   "show_all_content": "显示所有内容",
   "link_type": "链接类型",
-  "comment_edited_at_timestamp": "评论于 <1>{{timestamp}}</1> 被编辑",
-  "reason_reason": "原因: \"{{reason}}\".",
-  "click_here_to_show_original": "<1>点击这里</1> 显示原文。",
-  "click_here_to_hide_original": "<1>点击这里</1> 隐藏原文。",
   "loading": "加载中",
   "posted_by": "由...发布",
   "by": "由...发布",
@@ -393,5 +389,13 @@
   "go_to_settings_to_import_mod_account": "前往<1>设置</1>以导入您的版主账户",
   "post_form_rules_faq_prompt": "发帖前请阅读<rules>规则</rules>和<faq>常见问题</faq>。",
   "pending_mod_approval_reason": "AI 审核已将此帖子发送到版主队列。原因：\"{{reason}}\"。",
-  "flag": "旗帜"
+  "flag": "旗帜",
+  "show_replies": "显示回复",
+  "hide_replies": "隐藏回复",
+  "unhide": "显示",
+  "account_data": "账户数据",
+  "ban_duration_days": "封禁时长（天数）",
+  "challenge_answer": "挑战答案",
+  "ban": "封禁",
+  "timestamp": "时间戳"
 }