Add per-project sub-navigation to the sidebar's Projects nav item

Inside a specific project, the "Projects" item in the sidebar now shows
Overview/Shots/Assets/Tasks/Settings as sub-links (mirroring the existing
top-of-page ProjectTabs), with the active tab highlighted to match the
current route.

When the sidebar is collapsed to icons, the Projects icon still links
straight to /projects like any other nav item; hovering it reveals the
same 5 sub-links as a flyout menu (a controlled Popover, not a
DropdownMenu, so its own click-to-open behavior doesn't hijack the
icon's normal navigation click).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

frontend/src/components/layout/AppSidebar.vue

@@ -27,12 +27,65 @@
         <SidebarGroupLabel>Navigation</SidebarGroupLabel>
         <SidebarMenu>
           <SidebarMenuItem v-for="item in navigationItems" :key="item.title">
+            <!-- Collapsed sidebar + Projects (with an active project): hovering reveals sub-links,
+                 while the icon itself still navigates to /projects like any other nav item. -->
+            <div
+              v-if="item.title === 'Projects' && isCollapsed && projectTabs.length > 0"
+              @mouseenter="showProjectFlyout = true"
+              @mouseleave="showProjectFlyout = false"
+            >
+              <Popover :open="showProjectFlyout">
+                <PopoverAnchor>
+                  <SidebarMenuButton as-child :title="item.title">
+                    <router-link :to="item.url" class="flex items-center gap-2">
+                      <component :is="item.icon" class="size-4" />
+                      <span class="group-data-[collapsible=icon]:hidden">{{ item.title }}</span>
+                    </router-link>
+                  </SidebarMenuButton>
+                </PopoverAnchor>
+                <PopoverContent
+                  side="right"
+                  align="start"
+                  class="w-48 p-1"
+                  @open-auto-focus.prevent
+                  @mouseenter="showProjectFlyout = true"
+                  @mouseleave="showProjectFlyout = false"
+                >
+                  <router-link
+                    v-for="tab in projectTabs"
+                    :key="tab.id"
+                    :to="tab.route"
+                    class="flex items-center gap-2 rounded-sm px-2 py-1.5 text-sm hover:bg-accent hover:text-accent-foreground"
+                    :class="activeProjectTab === tab.id && 'bg-accent text-accent-foreground'"
+                    @click="showProjectFlyout = false"
+                  >
+                    <component :is="tab.icon" class="size-4" />
+                    <span>{{ tab.label }}</span>
+                  </router-link>
+                </PopoverContent>
+              </Popover>
+            </div>
+
+            <template v-else>
               <SidebarMenuButton as-child :tooltip="isCollapsed ? item.title : undefined">
                 <router-link :to="item.url" class="flex items-center gap-2">
                   <component :is="item.icon" class="size-4" />
                   <span class="group-data-[collapsible=icon]:hidden">{{ item.title }}</span>
                 </router-link>
               </SidebarMenuButton>
+
+              <!-- Project sub-navigation - shown under "Projects" when inside a specific project -->
+              <SidebarMenuSub v-if="item.title === 'Projects' && projectTabs.length > 0">
+                <SidebarMenuSubItem v-for="tab in projectTabs" :key="tab.id">
+                  <SidebarMenuSubButton as-child :is-active="activeProjectTab === tab.id">
+                    <router-link :to="tab.route" class="flex items-center gap-2">
+                      <component :is="tab.icon" class="size-4" />
+                      <span class="truncate">{{ tab.label }}</span>
+                    </router-link>
+                  </SidebarMenuSubButton>
+                </SidebarMenuSubItem>
+              </SidebarMenuSub>
+            </template>
           </SidebarMenuItem>
         </SidebarMenu>
       </SidebarGroup>
@@ -93,8 +146,9 @@
 </template>
 
 <script setup lang="ts">
-import { computed } from 'vue'
+import { computed, ref } from 'vue'
 import { useRoute } from 'vue-router'
+import { Popover, PopoverAnchor, PopoverContent } from '@/components/ui/popover'
 import {
   Sidebar,
   SidebarContent,
@@ -105,6 +159,9 @@ import {
   SidebarMenu,
   SidebarMenuButton,
   SidebarMenuItem,
+  SidebarMenuSub,
+  SidebarMenuSubButton,
+  SidebarMenuSubItem,
   useSidebar,
   SidebarProps
 } from '@/components/ui/sidebar'
@@ -120,6 +177,10 @@ import {
   Database,
   BarChart3,
   RotateCcw,
+  LayoutDashboard,
+  Camera,
+  Package,
+  ListTodo,
 } from 'lucide-vue-next'
 
 import { useAuthStore } from '@/stores/auth'
@@ -131,6 +192,7 @@ const authStore = useAuthStore()
 const { isCoordinatorOrAdmin } = usePermission()
 const { state } = useSidebar()
 const route = useRoute()
+const showProjectFlyout = ref(false)
 const user = computed(() => authStore.user)
 const userRole = computed(() => authStore.user?.role || 'artist')
 
@@ -142,6 +204,38 @@ const isOnShotPage = computed(() => {
   return route.path.endsWith('/shots') || route.path.includes('/project/')
 })
 
+// The project id when on a specific project's page (null on /projects, /projects/new, etc.)
+const currentProjectId = computed(() => {
+  const id = route.params.projectId
+  const parsed = typeof id === 'string' ? parseInt(id) : NaN
+  return isNaN(parsed) ? null : parsed
+})
+
+// Sub-nav items shown under the "Projects" nav item when inside a specific project
+const projectTabs = computed(() => {
+  const id = currentProjectId.value
+  if (id === null) return []
+  return [
+    { id: 'overview', label: 'Overview', icon: LayoutDashboard, route: `/projects/${id}` },
+    { id: 'shots', label: 'Shots', icon: Camera, route: `/projects/${id}/shots` },
+    { id: 'assets', label: 'Assets', icon: Package, route: `/projects/${id}/assets` },
+    { id: 'tasks', label: 'Tasks', icon: ListTodo, route: `/projects/${id}/tasks` },
+    { id: 'settings', label: 'Settings', icon: Settings, route: `/projects/${id}/settings` },
+  ]
+})
+
+const activeProjectTab = computed(() => {
+  const id = currentProjectId.value
+  if (id === null) return null
+  const path = route.path
+  if (path === `/projects/${id}`) return 'overview'
+  if (path.startsWith(`/projects/${id}/shots`)) return 'shots'
+  if (path.startsWith(`/projects/${id}/assets`)) return 'assets'
+  if (path.startsWith(`/projects/${id}/tasks`)) return 'tasks'
+  if (path.startsWith(`/projects/${id}/settings`)) return 'settings'
+  return null
+})
+
 const props = withDefaults(defineProps<SidebarProps>(), {
   collapsible: "icon",
 })