Refactor Assistant navigation and update HomePage button

Updated the AppShell and Sidebar components to streamline navigation for the Assistant section, consolidating assistant-related pages under a single "assistants" key. Removed deprecated assistant sub-items and adjusted the HomePage button to link to the new assistant navigation. Enhanced the AssistantPage with a list view for managing assistants, including mock data for demonstration.

src/components/layout/Sidebar.tsx

@@ -9,7 +9,6 @@ import {
   Clock3,
   Database,
   Wrench,
-  FileText,
   Home,
   PlayCircle,
   Video,
@@ -34,15 +33,6 @@ const mainItems: Array<{
   { key: "test", label: "测试助手", icon: PlayCircle },
 ];
 
-const assistantSubItems: Array<{
-  key: NavKey;
-  label: string;
-  icon: React.ComponentType<{ size?: number }>;
-}> = [
-  { key: "assistant-prompt", label: "提示词模式", icon: FileText },
-  { key: "assistant-workflow", label: "工作流模式", icon: Workflow },
-];
-
 const componentSubItems: Array<{
   key: NavKey;
   label: string;
@@ -59,8 +49,7 @@ export function Sidebar({
   onNavigate,
   onToggle,
 }: SidebarProps) {
-  const assistantActive =
-    active === "assistant-prompt" || active === "assistant-workflow";
+  const assistantActive = active === "assistants";
 
   const componentActive =
     active === "components-models" || active === "components-knowledge" || active === "components-tools";
@@ -106,46 +95,14 @@ export function Sidebar({
             label="控制台"
             onClick={() => onNavigate("home")}
           />
-
           <div className="pt-2">
-            {collapsed ? (
-              <div
-                className="flex h-8 items-center justify-center"
-                aria-hidden="true"
-                title="创建助手"
-              >
-                <span className="h-px w-6 rounded-full bg-hairline-strong" />
-              </div>
-            ) : (
-              <div
-                className={[
-                  "flex h-11 w-full items-center gap-3 rounded-full px-3 text-sm",
-                  assistantActive ? "text-foreground" : "text-muted-foreground",
-                ].join(" ")}
-              >
-                <Bot size={18} />
-                <span className="font-medium">创建助手</span>
-              </div>
-            )}
-
-            <div
-              className={[
-                "mt-1 space-y-1 transition-[padding] duration-300 ease-[cubic-bezier(0.22,1,0.36,1)]",
-                collapsed ? "pl-0" : "pl-5",
-              ].join(" ")}
-            >
-              {assistantSubItems.map((item) => (
-                <NavButton
-                  key={item.key}
-                  active={active === item.key}
-                  collapsed={collapsed}
-                  icon={item.icon}
-                  label={item.label}
-                  onClick={() => onNavigate(item.key)}
-                  small
-                />
-              ))}
-            </div>
+            <NavButton
+              active={assistantActive}
+              collapsed={collapsed}
+              icon={Bot}
+              label="创建助手"
+              onClick={() => onNavigate("assistants")}
+            />
           </div>
 
           <div className="pt-2">