A 42-year-old woman from Delhi presents with a 6-month history of a painless, progressively enlarging neck mass. On examination, she has a firm, fixed, 3 cm nodule in the right lobe of the thyroid with ipsilateral cervical lymphadenopathy. TSH is 2.1 mIU/L (normal). Fine-needle aspiration cytology (FNAC) shows cells arranged in a papillary pattern with nuclear grooves, intranuclear pseudoinclusions, and occasional psammoma bodies. What is the most likely diagnosis?