feat(nav): add Discover link for logged-in users

Made-with: Cursor

app/components/AppShell.vue

@@ -30,6 +30,7 @@ const displayName = computed(() => {
 })
 
 const homeNav = { label: '首页', to: '/', icon: 'i-lucide-house' } as const
+const discoverNav = { label: '发现', to: '/discover', icon: 'i-lucide-compass' } as const
 
 const consoleSubNav = [
   { label: '资料', to: '/me/profile', icon: 'i-lucide-user-round' },
@@ -43,9 +44,12 @@ const consoleDropdownItems = computed(() => [
   consoleSubNav.map((i) => ({ label: i.label, icon: i.icon, to: i.to })),
 ])
 
-/** 移动端汉堡菜单：首页 + 「控制台」分组下四个子项 */
+/** 移动端汉堡菜单：首页、发现 + 「控制台」分组下四个子项 */
 const mobileMenuItems = computed(() => [
-  [{ label: homeNav.label, icon: homeNav.icon, to: homeNav.to }],
+  [
+    { label: homeNav.label, icon: homeNav.icon, to: homeNav.to },
+    { label: discoverNav.label, icon: discoverNav.icon, to: discoverNav.to },
+  ],
   [{ type: 'label' as const, label: '控制台' }, ...consoleSubNav.map((i) => ({ label: i.label, icon: i.icon, to: i.to }))],
 ])
 
@@ -133,6 +137,18 @@ async function logout() {
                   navActive(homeNav.to) ? 'bg-elevated text-highlighted' : 'text-muted',
                 ]"
               />
+              <UButton
+                :to="discoverNav.to"
+                :icon="discoverNav.icon"
+                :label="discoverNav.label"
+                color="neutral"
+                variant="ghost"
+                size="sm"
+                :class="[
+                  'shrink-0 rounded-md',
+                  navActive(discoverNav.to) ? 'bg-elevated text-highlighted' : 'text-muted',
+                ]"
+              />
               <UDropdownMenu :items="consoleDropdownItems" :content="{ align: 'start' }">
                 <UButton
                   color="neutral"