fix: sort recipe names accent-folded for locale-aware ordering (#6853)

Recipe name sorting applied lower() to the raw name, so accented and
umlaut characters sorted by raw code point and landed after "Z"
(e.g. "Über" after "Zebra"). Sort by the existing unidecode-normalized
name column instead, so accented characters sort next to their base
letter. Works identically on SQLite and Postgres since the sort key is
a pre-computed ASCII column rather than a DB collation.

tests/unit_tests/repository_tests/test_recipe_repository.py

@@ -647,6 +647,40 @@ def test_order_by_last_made(unique_user: TestUser, h2_user: TestUser):
     assert [item.id for item in h2_query.items] == [recipe_2.id, recipe_1.id]
 
 
+def test_order_by_name_is_accent_folded(unique_user: TestUser):
+    # Names chosen so that raw code-point sorting (the previous behavior) would place the
+    # umlaut/accented entries after "Zebra". Accent-folded sorting must instead place them
+    # next to their base letter: "ärtsoppa" near "a", "Über" near "u". See GH #6853.
+    names = ["Zebra", "ärtsoppa", "Apple", "Über"]
+    recipes = [
+        unique_user.repos.recipes.create(Recipe(user_id=unique_user.user_id, group_id=unique_user.group_id, name=name))
+        for name in names
+    ]
+    recipe_ids = ", ".join(str(recipe.id) for recipe in recipes)
+
+    ascending = unique_user.repos.recipes.page_all(
+        PaginationQuery(
+            page=1,
+            per_page=-1,
+            order_by="name",
+            order_direction=OrderDirection.asc,
+            query_filter=f"id IN [{recipe_ids}]",
+        )
+    )
+    assert [item.name for item in ascending.items] == ["Apple", "ärtsoppa", "Über", "Zebra"]
+
+    descending = unique_user.repos.recipes.page_all(
+        PaginationQuery(
+            page=1,
+            per_page=-1,
+            order_by="name",
+            order_direction=OrderDirection.desc,
+            query_filter=f"id IN [{recipe_ids}]",
+        )
+    )
+    assert [item.name for item in descending.items] == ["Zebra", "Über", "ärtsoppa", "Apple"]
+
+
 def test_coalesce_last_made(unique_user: TestUser):
     dt = datetime.now(UTC)