ALTER TABLE "crm_leads" ADD COLUMN IF NOT EXISTS "description" text, ADD COLUMN IF NOT EXISTS "product_type" text, ADD COLUMN IF NOT EXISTS "priority" text, ADD COLUMN IF NOT EXISTS "estimated_value" double precision, ADD COLUMN IF NOT EXISTS "assigned_sales_owner_id" text, ADD COLUMN IF NOT EXISTS "assigned_at" timestamp with time zone, ADD COLUMN IF NOT EXISTS "assigned_by" text, ADD COLUMN IF NOT EXISTS "assignment_remark" text;