feat: Add Inbox view with task/appointment/email management

- Add InboxView.vue with full CRUD UI
- Add inbox to navigation (first item)
- Support filtering by status/type
- Show stats (due today, overdue, etc.)
- Quick status updates with checkbox
- Priority indicators and overdue warnings

src/router/index.js

@@ -18,6 +18,11 @@ const routes = [
         name: 'Dashboard',
         component: () => import('@/views/DashboardView.vue')
       },
+      {
+        path: 'inbox',
+        name: 'Inbox',
+        component: () => import('@/views/InboxView.vue')
+      },
       {
         path: 'contacts',
         name: 'Contacts',