feat: add Russian localization and independent STT languages

components/ai-elements/message.tsx

@@ -1,4 +1,6 @@
 "use client";
+import { useI18n } from "@/components/i18n";
+
 
 import { Button } from "@/components/ui/button";
 import {
@@ -31,6 +33,8 @@ import {
 import remarkBreaks from "remark-breaks";
 import {
   Streamdown,
+  defaultTranslations,
+  type StreamdownTranslations,
   type PluginConfig,
 } from "streamdown";
 import { mdComponents } from "@/components/md-blocks";
@@ -264,11 +268,12 @@ export const MessageBranchPrevious = ({
   children,
   ...props
 }: MessageBranchPreviousProps) => {
+	const { t } = useI18n();
   const { goToPrevious, totalBranches } = useMessageBranch();
 
   return (
     <Button
-      aria-label="Previous branch"
+      aria-label={t("Previous branch")}
       disabled={totalBranches <= 1}
       onClick={goToPrevious}
       size="icon-sm"
@@ -287,11 +292,12 @@ export const MessageBranchNext = ({
   children,
   ...props
 }: MessageBranchNextProps) => {
+	const { t } = useI18n();
   const { goToNext, totalBranches } = useMessageBranch();
 
   return (
     <Button
-      aria-label="Next branch"
+      aria-label={t("Next branch")}
       disabled={totalBranches <= 1}
       onClick={goToNext}
       size="icon-sm"
@@ -310,6 +316,7 @@ export const MessageBranchPage = ({
   className,
   ...props
 }: MessageBranchPageProps) => {
+	const { t } = useI18n();
   const { currentBranch, totalBranches } = useMessageBranch();
 
   return (
@@ -320,7 +327,7 @@ export const MessageBranchPage = ({
       )}
       {...props}
     >
-      {currentBranch + 1} of {totalBranches}
+      {currentBranch + 1}{" "}{t("of")}{" "}{totalBranches}
     </ButtonGroupText>
   );
 };
@@ -357,6 +364,8 @@ export const streamdownPlugins = {
 
 export const MessageResponse = memo(
   ({ className, children, ...props }: MessageResponseProps) => {
+    const { t } = useI18n();
+    const translations = Object.fromEntries(Object.entries(defaultTranslations).map(([key, text]) => [key, t(text)])) as Partial<StreamdownTranslations>;
     // Legacy backslash delimiters are converted in a single linear scan;
     // native dollar math passes through to Streamdown unchanged. Incomplete
     // legacy spans are left for a later render when their closer arrives.
@@ -373,6 +382,7 @@ export const MessageResponse = memo(
           "lh-prose size-full [&>*:first-child]:mt-0 [&>*:last-child]:mb-0",
           className
         )}
+        translations={translations}
         components={mdComponents}
         plugins={streamdownPlugins}
         {...props}

components/ai-elements/reasoning.tsx

@@ -1,4 +1,5 @@
 "use client";
+import { useI18n } from "@/components/i18n";
 
 import { useControllableState } from "@radix-ui/react-use-controllable-state";
 import { blurAfterPointerClick } from "@/components/focus-hygiene";
@@ -134,20 +135,22 @@ export type ReasoningTriggerProps = ComponentProps<
    for a few seconds"), bookkeeping for information we knowingly lose. The
    label pairs with the user's collapsed "Your thinking" rows — one
    language; motion (spinner + shimmer) stays the working signal. */
-const defaultGetThinkingMessage = (isStreaming: boolean) => {
+const DefaultThinkingMessage = ({ isStreaming }: { isStreaming: boolean }) => {
+  const { t } = useI18n();
   if (isStreaming) {
-    return <Shimmer duration={1}>Thinking...</Shimmer>;
+    return <Shimmer duration={1}>{t("Thinking...")}</Shimmer>;
   }
-  return <p>AGENT’S THINKING</p>;
+  return <p>{t("AGENT’S THINKING")}</p>;
 };
 
 export const ReasoningTrigger = memo(
   ({
     className,
     children,
-    getThinkingMessage = defaultGetThinkingMessage,
+    getThinkingMessage = (isStreaming) => <DefaultThinkingMessage isStreaming={isStreaming} />,
     ...props
   }: ReasoningTriggerProps) => {
+	const { t } = useI18n();
     const { isStreaming, isOpen } = useReasoning();
 
     return (
@@ -175,7 +178,7 @@ export const ReasoningTrigger = memo(
                 the component default (h-3) — IDENTICAL to the placeholder
                 spinner (owner, 2026-10-02): the handoff between the two
                 states must be visually seamless, one size everywhere. */}
-            {isStreaming && <BrailleSpinner label="Thinking" />}
+            {isStreaming && <BrailleSpinner label={t("Thinking")} />}
             {getThinkingMessage(isStreaming)}
             <ChevronDownIcon
               className={cn(