fix: resolve CI issues - clean up unused imports and fix linting errors

app/tests/test_changelog_generator.py

@@ -65,7 +65,8 @@ class TestChangelogGenerator:
         assert "## Features" in result
         assert "## Bug Fixes" in result
         assert "**feat(api):** add endpoint" in result
-        assert "**feat(ui):** without placeholders"
+        assert "**feat(ui):** add button" in result
+        assert "**fix(db):** fix bug" in result
 
     def test_generate_simple_no_commits_raises_error(self, changelog_generator):
         """Test that generate_simple raises error when no commits."""