fix(chat): restrict thinking prefix to claude

Initialize the composer thinking mode from localStorage so reloads keep the user's

selected mode instead of falling back to Standard.

Keep the chosen mode after sending because the selector behaves like a

preference, not a one-shot modifier for a single prompt.

src/components/chat/hooks/useChatComposerState.ts

@@ -143,6 +143,21 @@ const createFakeSubmitEvent = () => {
   return { preventDefault: () => undefined } as unknown as FormEvent<HTMLFormElement>;
 };
 
+const THINKING_MODE_STORAGE_KEY = 'chat-thinking-mode';
+
+const getInitialThinkingMode = () => {
+  if (typeof window === 'undefined') {
+    return 'none';
+  }
+
+  const savedMode = safeLocalStorage.getItem(THINKING_MODE_STORAGE_KEY);
+  if (!savedMode) {
+    return 'none';
+  }
+
+  return thinkingModes.some((mode) => mode.id === savedMode) ? savedMode : 'none';
+};
+
 const getNotificationSessionSummary = (
   selectedSession: ProjectSession | null,
   fallbackInput: string,
@@ -204,7 +219,7 @@ export function useChatComposerState({
   const [uploadingImages, setUploadingImages] = useState<Map<string, number>>(new Map());
   const [imageErrors, setImageErrors] = useState<Map<string, string>>(new Map());
   const [isTextareaExpanded, setIsTextareaExpanded] = useState(false);
-  const [thinkingMode, setThinkingMode] = useState('none');
+  const [thinkingMode, setThinkingMode] = useState(getInitialThinkingMode);
   const [commandModalPayload, setCommandModalPayload] = useState<CommandModalPayload | null>(null);
 
   const textareaRef = useRef<HTMLTextAreaElement>(null);
@@ -564,7 +579,7 @@ export function useChatComposerState({
 
       let messageContent = currentInput;
       const selectedThinkingMode = thinkingModes.find((mode: { id: string; prefix?: string }) => mode.id === thinkingMode);
-      if (selectedThinkingMode && selectedThinkingMode.prefix) {
+      if (provider === 'claude' && selectedThinkingMode && selectedThinkingMode.prefix) {
         messageContent = `${selectedThinkingMode.prefix}: ${currentInput}`;
       }
 
@@ -749,7 +764,6 @@ export function useChatComposerState({
       setUploadingImages(new Map());
       setImageErrors(new Map());
       setIsTextareaExpanded(false);
-      setThinkingMode('none');
 
       if (textareaRef.current) {
         textareaRef.current.style.height = 'auto';
@@ -795,6 +809,10 @@ export function useChatComposerState({
     inputValueRef.current = input;
   }, [input]);
 
+  useEffect(() => {
+    safeLocalStorage.setItem(THINKING_MODE_STORAGE_KEY, thinkingMode);
+  }, [thinkingMode]);
+
   useEffect(() => {
     if (!selectedProjectId) {
       return;