fix: Register staff notifications route and fix import paths

## 🐛 Bug Fixes

**App.tsx:**
- ✅ Added StaffNotifications import
- ✅ Registered `/settings/notifications/staff` route

**Staff/Channels.tsx:**
- ✅ Fixed SettingsCard import path (../../components/SettingsCard)
- ✅ Fixed ChannelConfig import path (../ChannelConfig)

**Staff.tsx:**
- ✅ Removed recipientType prop from Templates (not supported yet)

---

**Status:** Staff notifications route should now work correctly

admin-spa/src/routes/Settings/Notifications/Staff.tsx

@@ -41,7 +41,7 @@ export default function StaffNotifications() {
         </TabsContent>
 
         <TabsContent value="templates" className="space-y-4">
-          <NotificationTemplates recipientType="staff" />
+          <NotificationTemplates />
         </TabsContent>
       </Tabs>
     </SettingsLayout>