A 45-year-old woman from a tribal area in Odisha presents with progressive vision loss, eye irritation, and recurrent episodes of eye redness over 15 years. On slit-lamp examination, she has upper tarsal scarring, trichiasis with inturned eyelashes, and a hazy cornea with neovascularization. She reports a history of recurrent conjunctivitis since childhood. What is the most likely stage of trachoma, and what is the immediate management priority?