Allow store deletion when only archived lists reference it

Archived lists are no longer part of anyone''s workflow, so they
shouldn''t block a store from being deleted. The handler now blocks
only on non-archived lists and purges archived ones (items cascade)
in the same transaction.

Also grooms BACKLOG.md to remove items already shipped (Family/multi-
tenant epic, password reset, email invites, auth rate limiting,
picked-up-vs-removed, per-store sections base feature, add-recipe-to-
list, store delete confirm + duplicate-name 409).

src/backend/YesChef.Api.IntegrationTests/Features/StoreEndpointsTests.cs

@@ -70,7 +70,7 @@ public class StoreEndpointsTests : AuthenticatedIntegrationTest
     }
 
     [Test]
-    public async Task Delete_blocks_when_store_has_lists()
+    public async Task Delete_blocks_when_store_has_active_lists()
     {
         var store = await Data.CreateStoreAsync();
         await Data.CreateListAsync(b => b.ForStore(store).CreatedBy(User));
@@ -81,6 +81,19 @@ public class StoreEndpointsTests : AuthenticatedIntegrationTest
         await Assert.That(await UseDbAsync(db => db.Stores.AnyAsync(s => s.Id == store.Id))).IsTrue();
     }
 
+    [Test]
+    public async Task Delete_succeeds_when_store_only_has_archived_lists()
+    {
+        var store = await Data.CreateStoreAsync();
+        await Data.CreateListAsync(b => b.ForStore(store).CreatedBy(User).Archived());
+
+        var response = await Client.DeleteAsync($"/api/stores/{store.Id}");
+
+        await Assert.That(response.StatusCode).IsEqualTo(HttpStatusCode.NoContent);
+        await Assert.That(await UseDbAsync(db => db.Stores.AnyAsync(s => s.Id == store.Id))).IsFalse();
+        await Assert.That(await UseDbAsync(db => db.ShoppingLists.AnyAsync(l => l.StoreId == store.Id))).IsFalse();
+    }
+
     [Test]
     public async Task Create_returns_409_for_duplicate_name()
     {