refactor(frontend): clean up chat components and improve sidebar styling for better layout

Author: Sma1lboy

frontend/src/components/chat/chat-bottombar.tsx

@@ -126,7 +126,7 @@ export default function ChatBottombar({
                   <button
                     type="button"
                     onClick={() => removeAttachment(index)}
-                    className="absolute -top-1 -right-1 size-5 bg-red-500 rounded-full flex items-center justify-center text-white opacity-0 group-hover:opacity-100 transition-opacity"
+                    className="absolute -top-1 -right-1 size-5 rounded-full flex items-center justify-center text-white opacity-0 group-hover:opacity-100 transition-opacity"
                   >
                     <X className="size-3" />
                   </button>

frontend/src/components/sidebar.tsx

@@ -98,13 +98,6 @@ function ChatSideBarComponent({
   const [currentChatid, setCurrentChatid] = useState('');
   const { setCurProject, pollChatProject } = useContext(ProjectContext);
 
-  const handleNewChat = useCallback(() => {
-    router.push('/');
-    setCurrentChatid('');
-    const event = new Event(EventEnum.NEW_CHAT);
-    window.dispatchEvent(event);
-  }, [router]);
-
   const handleChatSelect = useCallback(
     (chatId: string) => {
       setCurrentChatid(chatId);
@@ -238,8 +231,8 @@ function ChatSideBarComponent({
 
         {/* Footer Settings */}
         <SidebarFooter
-          className={`mt-auto border-t border-gray-200 dark:border-gray-700 ${
-            isCollapsed ? 'flex justify-center px-0' : 'px-3'
+          className={`mt-auto border-t border-gray-200  dark:border-gray-700 ${
+            isCollapsed ? 'flex justify-center items-center  px-0' : 'px-3'
           }`}
         >
           <UserSettingsBar isSimple={false} />

frontend/src/components/ui/sidebar.tsx

@@ -290,8 +290,8 @@ const SidebarRail = React.forwardRef<
 >(({ className, setIsSimple, isSimple, ...props }, ref) => {
   const { toggleSidebar } = useSidebar();
   const handleClick = (event: React.MouseEvent<HTMLButtonElement>) => {
-    toggleSidebar(); // 保留原有的逻辑
-    setIsSimple(!isSimple); // 更新 isSimple 状态
+    toggleSidebar();
+    setIsSimple(!isSimple);
   };
 
   return (

frontend/src/components/user-settings-bar.tsx

@@ -89,7 +89,6 @@ export const UserSettingsBar = ({ isSimple }: UserSettingsProps) => {
           />
           <AvatarFallback>{avatarFallback}</AvatarFallback>
         </SmallAvatar>
-        {!isSimple && <span className="truncate">{displayUsername}</span>}
       </Button>
     );
   }, [