Rework the lists view: form below list, drop description, add count

HomeView now shows a "You have N lists." summary above the list, moves the
new-list form beneath the list, and drops the description input (title only).
lists store createList() loses its description parameter.

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

web/src/stores/lists.ts

@@ -23,11 +23,11 @@ export const useListsStore = defineStore('lists', () => {
     }
   }
 
-  async function createList(title: string, description: string): Promise<TodoList> {
+  async function createList(title: string): Promise<TodoList> {
     const { list } = await apiRequest<{ list: TodoList }>('/lists', {
       method: 'POST',
       auth: true,
-      body: { title, description },
+      body: { title },
     })
 
     // Re-fetch so the new list lands in its correct alphabetical position.