fix(ai-chat): always show generic "AI is typing…" indicator

The typing indicator rendered "<role name> is typing…". Show a generic
"AI is typing…" instead and keep the role/identity name only in the
dimmed interlocutor label above the typing dots.

- typing line now always renders t("AI is typing…")
- add the "AI is typing…" key to en-US and ru-RU locales
- sync stale doc comments that referenced the old text

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/client/public/locales/en-US/translation.json

@@ -1147,6 +1147,7 @@
   "Take a look at the current document": "Take a look at the current document",
   "AI agent is typing…": "AI agent is typing…",
   "{{name}} is typing…": "{{name}} is typing…",
+  "AI is typing…": "AI is typing…",
   "Send": "Send",
   "Stop": "Stop",
   "Chat menu": "Chat menu",

apps/client/public/locales/ru-RU/translation.json

@@ -672,6 +672,7 @@
   "Take a look at the current document": "Посмотри текущий документ",
   "AI agent is typing…": "AI-агент печатает…",
   "{{name}} is typing…": "{{name}} печатает…",
+  "AI is typing…": "AI печатает…",
   "Agent role": "Роль агента",
   "AI chat": "AI-чат",
   "AI chat is disabled for this workspace.": "AI-чат отключён для этого рабочего пространства.",

apps/client/src/features/ai-chat/components/message-list.tsx

@@ -43,7 +43,7 @@ interface MessageListProps {
 const BOTTOM_THRESHOLD = 40;
 
 /**
- * Whether to show the standalone "AI agent is typing…" indicator. It bridges the
+ * Whether to show the standalone "AI is typing…" indicator. It bridges the
  * gap between sending and the first streamed content, so it shows only while a
  * turn is in flight AND the latest assistant message has nothing visible yet:
  *  - the last message is still the user's (assistant hasn't started a row), or

apps/client/src/features/ai-chat/components/show-typing-indicator.test.ts

@@ -5,7 +5,7 @@ import { showTypingIndicator } from "@/features/ai-chat/components/message-list.
 /**
  * Pure-helper tests for the typing-indicator bridging logic that the internal
  * chat and the public share widget now share. This is the behavior that decides
- * whether the animated "AI agent is typing…" placeholder shows in the gap
+ * whether the animated "AI is typing…" placeholder shows in the gap
  * between sending and the first streamed token.
  */
 const msg = (

apps/client/src/features/ai-chat/components/typing-indicator.tsx

@@ -19,8 +19,10 @@ interface TypingIndicatorProps {
  * the real assistant message once content starts arriving.
  *
  * Mirrors the assistant row layout in MessageItem (the dimmed label), so it reads
- * as the assistant's bubble taking shape. The label and typing line use the
- * configured identity name when provided, otherwise the generic "AI agent".
+ * as the assistant's bubble taking shape. The dimmed label uses the configured
+ * identity name when provided (otherwise the generic "AI agent"), while the
+ * typing line is always the generic "AI is typing…" (it never includes the
+ * role/identity name).
  */
 export default function TypingIndicator({ assistantName }: TypingIndicatorProps) {
   const { t } = useTranslation();
@@ -38,7 +40,7 @@ export default function TypingIndicator({ assistantName }: TypingIndicatorProps)
           <span />
         </span>
         <Text size="sm" c="dimmed">
-          {name ? t("{{name}} is typing…", { name }) : t("AI agent is typing…")}
+          {t("AI is typing…")}
         </Text>
       </Group>
     </Box>