Add sick routes to backend and frontend; update routing and UI components for sickness tracking

frontend/src/router/index.js

@@ -12,6 +12,7 @@ import OAuthCallback from '../views/OAuthCallback.vue'
 import WeekOverview from '../views/WeekOverview.vue'
 import Timefix from '../views/Timefix.vue'
 import Vacation from '../views/Vacation.vue'
+import Sick from '../views/Sick.vue'
 
 const router = createRouter({
   history: createWebHistory(import.meta.env.BASE_URL),
@@ -70,6 +71,12 @@ const router = createRouter({
       component: Vacation,
       meta: { requiresAuth: true }
     },
+    {
+      path: '/bookings/sick',
+      name: 'sick',
+      component: Sick,
+      meta: { requiresAuth: true }
+    },
     {
       path: '/entries',
       name: 'entries',