Add /clear command

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

web/src/i18n/en.ts

@@ -1143,6 +1143,8 @@ export const en = {
   "stats.table.agent": "by agent",
   "stats.table.user": "by user",
   "stats.table.session": "top chats",
+  "command.clear": "Forget the conversation so far (the chat stays visible)",
+  "chat.cleared": "Context cleared – the model no longer sees the messages above",
 };
 
 export type Messages = Record<keyof typeof en, string>;