feat(admin): add demand lead management and site config modules

- Add lead list page with keyword, date range and source filtering, plus per-row lead status updates
- Extend site configuration types and admin editor to support demand page modules: hero, feature cards, contact form and product recommendations
- Update admin navigation, tab handling and type definitions for the new lead list tab and demand modules

src/components/admin/AdminShell.tsx

@@ -33,6 +33,9 @@ const sidebarGroups: { id: string; label: string; items: { id: Tab; label: strin
 ];
 
 const tabs = sidebarGroups.flatMap((group) => group.items);
+const hiddenTabs: Partial<Record<Tab, { label: string; description: string }>> = {
+  leadList: { label: "线索查询跟进", description: "表单查询和状态流转" },
+};
 
 export function AdminShell({ onLogout }: { onLogout: () => void }) {
   const [activeTab, setActiveTab] = useState<Tab>("structure");
@@ -50,7 +53,7 @@ export function AdminShell({ onLogout }: { onLogout: () => void }) {
     setHasUnsavedChanges(false);
   }, [activeTab]);
 
-  const activeMeta = useMemo(() => tabs.find((tab) => tab.id === activeTab), [activeTab]);
+  const activeMeta = useMemo(() => tabs.find((tab) => tab.id === activeTab) ?? hiddenTabs[activeTab], [activeTab]);
   const activeLabel = activeMeta?.label ?? "";
   const activeDescription = activeMeta?.description ?? "";
 
@@ -125,6 +128,8 @@ export function AdminShell({ onLogout }: { onLogout: () => void }) {
           <StructurePage key="destination-workbench" fixedPage="destination" onJump={setActiveTab} onDirtyChange={setHasUnsavedChanges} notify={notify} />
         ) : activeTab === "products" ? (
           <ProductsPage destinations={destinations} onDirtyChange={setHasUnsavedChanges} notify={notify} />
+        ) : activeTab === "leads" ? (
+          <StructurePage key="demand-workbench" fixedPage="demand" onJump={setActiveTab} onDirtyChange={setHasUnsavedChanges} notify={notify} />
         ) : (
           <LeadsPage notify={notify} />
         )}