A 30-year-old female presents to an outpatient clinic complaining of persistent right shoulder discomfort for the past six weeks. She is a professional painter whose work involves extensive overhead reaching. The pain is dull, insidious in onset, and is exacerbated by her work activities, particularly when reaching above her head or pushing forward. She denies any specific traumatic event, numbness, or tingling in her arm or hand. Her past medical history is unremarkable, aside from seasonal allergies managed with over-the-counter antihistamines. On physical examination, her vital signs are stable. Inspection of her back reveals a noticeable prominence of the medial border and inferior angle of the right scapula, especially when she attempts to push against a wall. Palpation around the shoulder reveals no tenderness, and range of motion is full but reproduces mild discomfort with forward flexion beyond 90 degrees. Motor strength testing demonstrates intact deltoid, biceps, triceps, and rotator cuff muscles (5/5). Sensation is intact throughout her right upper extremity. Deep tendon reflexes are symmetrical and normal. Given her presentation, what is the most likely diagnosis and the recommended initial management strategy?