hitoyaCute/Arduino_calculator ? reverse-engineered prompt

Build me a small Arduino calculator project for an Arduino Uno R3 with a 0.91 inch SSD1306 OLED and a 4x4 keypad.

I want it to feel like a simple little calculator UI on the screen, not just serial output. It should let me type arithmetic expressions, show what I am entering, evaluate the result, and handle basic mistakes cleanly so it does not crash or freeze. Keep it practical for a school project, but make it solid and fun to use.

Please use the OLED for the display and make the keypad input feel responsive. I’d also like it set up so I can compile, upload, and monitor it easily with make and arduino cli, since that is how I want to work on it. If you need to look up current docs for the OLED library or arduino cli details, go ahead and do that.