CREATE TABLE sales_users(
 id INT AUTO_INCREMENT PRIMARY KEY,
 username VARCHAR(100) UNIQUE NOT NULL,
 password_hash VARCHAR(255) NOT NULL,
 full_name VARCHAR(150),
 role ENUM('manager','seller') DEFAULT 'seller',
 created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);
CREATE TABLE lead_assignments(
 id INT AUTO_INCREMENT PRIMARY KEY,
 lead_id INT NOT NULL,
 seller_id INT NOT NULL,
 status VARCHAR(50) DEFAULT 'new',
 created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
 UNIQUE KEY uniq_lead(lead_id)
);
CREATE TABLE lead_notes(
 id INT AUTO_INCREMENT PRIMARY KEY,
 lead_id INT NOT NULL,
 user_id INT NOT NULL,
 note TEXT,
 created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);