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/de/default.json

@@ -144,10 +144,6 @@
   "show_worksafe_boards_only": "Nur sichere Boards anzeigen",
   "show_all_content": "Alle Inhalte anzeigen",
   "link_type": "Linktyp",
-  "comment_edited_at_timestamp": "Kommentar bearbeitet am <1>{{timestamp}}</1>",
-  "reason_reason": "Grund: \"{{reason}}\".",
-  "click_here_to_show_original": "<1>Hier klicken</1>, um das Original anzuzeigen.",
-  "click_here_to_hide_original": "<1>Hier klicken</1>, um das Original zu verstecken.",
   "loading": "Laden",
   "posted_by": "Geschrieben von",
   "by": "von",
@@ -393,5 +389,13 @@
   "go_to_settings_to_import_mod_account": "Gehe zu <1>Einstellungen</1>, um dein Moderatorkonto zu importieren",
   "post_form_rules_faq_prompt": "Bitte lesen Sie die <rules>Regeln</rules> und die <faq>FAQ</faq>, bevor Sie posten.",
   "pending_mod_approval_reason": "Die KI-Moderation hat diesen Beitrag in die Moderationswarteschlange verschoben. Grund: \"{{reason}}\".",
-  "flag": "Flagge"
+  "flag": "Flagge",
+  "show_replies": "Antworten anzeigen",
+  "hide_replies": "Antworten ausblenden",
+  "unhide": "einblenden",
+  "account_data": "kontodaten",
+  "ban_duration_days": "bannierungsdauer in tagen",
+  "challenge_answer": "herausforderungsantwort",
+  "ban": "sperren",
+  "timestamp": "Zeitstempel"
 }