A 45-year-old woman with poorly controlled type 2 diabetes mellitus presents with redness, warmth and tenderness of her left lower leg. The affected area is ill-defined, extending from the ankle to mid-calf, without abscess or systemic features. She has no MRSA risk factors. According to Therapeutic Guidelines, which oral antibiotic is most appropriate for initial management of uncomplicated non-purulent cellulitis in the community?