Notes

Implementation Choices

QR codes are generated server-side with the Python qrcode package and returned as an SVG data URL from session creation.
live_histogram is pushed on every accepted submission. There is no throttling in v1 because the acceptance load is small and this keeps behavior simple.
WebSocket broadcast sends are queued as background tasks. This prevents one slow classroom device from blocking state transitions or auto-close.
The optional observer page exists as a placeholder only. The spec explicitly marks it optional.
Tests use one FastAPI TestClient portal for multi-student WebSocket simulation. Each socket is opened after joining as that student, and the stored socket identity remains stable after the cookie is overwritten for the next simulated student.
Python 3.14.4 was used locally. The project requires Python 3.11 or newer.

The admin frontend includes a compact one-question sample in the Add Pool modal for convenience. The full 10-question Week 9 pool is in examples/week9_pool.json.
FastAPI emits a deprecation warning for on_event under the installed version. Startup works correctly, and the warning is not user-facing.