Create a working calculator app.
Choose the technology yourself.
Run it.
Test it.
Fix any issues you find.
Do not ask me questions unless you are genuinely blocked.
The deliverable should be a calculator application that actually runs and has been tested and repaired, using a technology stack chosen by the implementer. Minimum capabilities include digit and decimal entry, the four basic operations, clear, backspace, sign toggle, and equals. A strong implementation should also handle precedence, chained calculations, keyboard input, error states, and number formatting. The calculation core should be deterministic; division by zero, malformed expressions, overflow, and floating-point display noise should be handled intelligibly without crashing the UI. The handoff should include run instructions, a test method, and evidence that discovered defects were fixed.