A 35-year-old man from Delhi presents with a 6-month history of recurrent seizures occurring 2–3 times per week. Seizures are characterized by sudden loss of consciousness, rhythmic jerking of all four limbs lasting 60–90 seconds, followed by post-ictal confusion for 10–15 minutes. There is no aura or focal onset. He has no prior history of head injury, meningitis, or stroke. Neurological examination between seizures is normal. MRI brain is normal. EEG shows 3 Hz spike-and-wave discharges. What is the most likely diagnosis?