I need a quick-turn upgrade to my existing Google Sheet so every invoice is calculated and exported flawlessly. Using Google Apps Script, please build the custom formulas and logic that pull line items, apply tax or discounts, calculate totals, and push the results into a neatly formatted invoice tab. When the numbers are ready, the same script should create a PDF, name it with the invoice number and client name, and save it to a Drive folder I’ll share. If you can add a one-click email send, that’s a bonus. Speed matters—I’d like this live and tested within the next couple of days, so only bid if you can start right away and show a sample of similar work. Once hired I’ll hand over the sheet and the template you can build on.