A 38-year-old man from Bangalore presents with recurrent nephrolithiasis and persistent hypertension (BP 158/96 mmHg). Serum calcium is 11.2 mg/dL (normal 8.5–10.5), phosphate 2.8 mg/dL, and PTH 185 pg/mL (normal 15–65). On further questioning, he reports a 3-year history of recurrent peptic ulcer disease refractory to standard PPI therapy, and his 12-year-old son has recently been diagnosed with a pituitary adenoma secreting growth hormone. Imaging of the parathyroid glands shows a 1.8 cm nodule. What is the most likely diagnosis?