refactor(studio): rename 笔记本 to 空间 in workspace nav and notebook pages

统一术语:侧边栏「新建笔记本/所有笔记本」、笔记列表与笔记本管理页的
新建按钮与弹窗标题，全部由"笔记本"改为"空间"。

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend-web/src/components/workspace/workspace-nav-studio.tsx

@@ -91,14 +91,14 @@ export function WorkspaceNavStudio() {
 
           <CollapsibleContent>
             <SidebarMenu className="mt-0.5 gap-0.5">
-              {/* 新建笔记本 */}
+              {/* 新建空间 */}
               <SidebarMenuItem>
                 <SidebarMenuButton
                   className={cn(NAV_ITEM_CLASS)}
                   onClick={() => { setDialogOpen(true); setError(""); setName(""); }}
                 >
                   <Plus className="shrink-0" />
-                  <span>新建笔记本</span>
+                  <span>新建空间</span>
                 </SidebarMenuButton>
               </SidebarMenuItem>
 
@@ -121,7 +121,7 @@ export function WorkspaceNavStudio() {
                 </SidebarMenuItem>
               ))}
 
-              {/* 所有笔记本 */}
+              {/* 所有空间 */}
               {notebooks.length > 0 && (
                 <SidebarMenuItem>
                   <SidebarMenuButton
@@ -130,8 +130,8 @@ export function WorkspaceNavStudio() {
                     className={cn(NAV_ITEM_CLASS)}
                   >
                     <Link to="/page/workspace/studio/notebooks">
-                      <span className="mr-0.5 text-base leading-none">···</span>
-                      <span>所有笔记本</span>
+                      {/* <span className="mr-0.5 text-base leading-none">···</span> */}
+                      <span>所有空间</span>
                     </Link>
                   </SidebarMenuButton>
                 </SidebarMenuItem>
@@ -144,7 +144,7 @@ export function WorkspaceNavStudio() {
       <Dialog open={dialogOpen} onOpenChange={(v) => !creating && setDialogOpen(v)}>
         <DialogContent className="sm:max-w-md">
           <DialogHeader>
-            <DialogTitle>新建笔记本</DialogTitle>
+            <DialogTitle>新建空间</DialogTitle>
           </DialogHeader>
           <div className="flex flex-col gap-4 pt-2">
             <input