INPUT — DealContext A + B (from Step 3)
deal_a: {brand:"Hyundai", price:1464000, perks:[...]}
deal_b: {brand:"Kia", price:1450000, perks:[...]}
cot_winner: "CRETA_2024" confidence: 0.87
trade_off: "Creta costs ₹14k more but 0.5 kmpl better mileage"
OUTPUT — LeadPayload appended to leads.json
{ lead_tag: "HOT_LEAD", engagement_score: 90,
modules_completed: ["intent","recommend","brand_bot","deal"],
chosen_sku: "CRETA_2024", offered_price: 1464000,
user: {name:"...", phone:"...", city:"..."},
timestamp: "2024-01-15T14:32:00Z" }