CREATE TABLE lead_documents (
    id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
    lead_id INT UNSIGNED NOT NULL,
    label VARCHAR(120) NOT NULL,
    storage_path VARCHAR(255) NOT NULL,
    mime_type VARCHAR(120) NULL,
    file_size INT UNSIGNED NULL,
    uploaded_by INT UNSIGNED NULL,
    uploaded_at DATETIME NULL,
    created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
    updated_at DATETIME NULL DEFAULT NULL ON UPDATE CURRENT_TIMESTAMP,
    CONSTRAINT fk_lead_documents_lead FOREIGN KEY (lead_id) REFERENCES leads (id) ON DELETE CASCADE,
    CONSTRAINT fk_lead_documents_user FOREIGN KEY (uploaded_by) REFERENCES users (id) ON DELETE SET NULL,
    INDEX idx_lead_documents_lead (lead_id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;