A 28-year-old female sex worker from Delhi attends the ICTC (Integrated Counselling and Testing Centre) for routine screening. Her HIV ELISA is positive, and Western blot confirms HIV-1 infection. CD4 count is 320 cells/μL. She is asymptomatic except for oral candidiasis. She has no history of antiretroviral therapy. What is her current WHO clinical stage, and what is the most appropriate next step in management?