Merge branch 'mock' into 'master'

uv run -m poolpay --mock

```

The mock card reader will listen on the command line for an integer card id, usually followed by `r` to simulate card removal. Quitting the program should work via <kbd>Ctrl</kbd>+<kbd>C/<kbd>, although it seems like not all threads immediately terminate, i.e., you might need to press it several times.

The mock card reader will listen on the command line for an integer card id, usually followed by `r` to simulate card removal. Quitting the program works via <kbd>Ctrl</kbd>+<kbd>C/<kbd>.

## License

from __future__ import annotations

import sys

from collections.abc import Callable

from dataclasses import dataclass, field

    def on_card_placed(self, handle_card: Callable[[CardReader], None]) -> None:

        while True:

            line = input("Card ID (int) or 'r' to remove card> ").strip()

            print("Card ID (int) or 'r' to remove card> ", end="", flush=True)

            # Using sys.stdin.readline instead of input seems to avoid 'Fatal Python error: _enter_buffered_busy:

            # could not acquire lock for <_io.BufferedReader name='<stdin>'> at interpreter shutdown,

            # possibly due to daemon threads' on terminate. I don't know why (does input hold a lock on stdin,

            # but readline doesn't?), but given that this is only for the mock mode, I'll accept this for now.

            line = sys.stdin.readline().strip()

            if line.lower() == "r":

                if self._card_id is not None:

    def run(self) -> None:

        pygame.init()

        pygame.display.set_caption("PoolPay")

        while True:

            request = self._request_queue.get(block=True)