You are a senior software developer. I have a bug in my banking app. A user entered 15000 as the receiver and 10000 as the pay side. This caused a 10000 gap in the balance sheet. Please search my codebase for files related to 'cash' or 'withdrawal'. Think step-by-step and explain where the logic error is. Then, show me how to fix it. Also, add a rule to make sure the numbers match before saving. A...