Add Turtle screen, game loop and entry point (MIL-003)

Task: MIL-003#1
Task: MIL-003#2
Task: MIL-003#3
Task: MIL-003#4
Task: MIL-003#5
Task: MIL-003#6

src/us_states_game/main.py

@@ -0,0 +1,43 @@
+"""Entry point of the U.S. States Game and its composition root.
+
+@file main.py
+@brief Wires the Turtle screen, the states and the game loop together.
+"""
+
+import argparse
+import logging
+from collections.abc import Sequence
+
+from us_states_game.game import run_game
+from us_states_game.storage import load_states
+from us_states_game.turtle_screen import TurtleScreen
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    """Play the game once.
+
+    @param argv Command line arguments; defaults to `sys.argv[1:]`.
+    @return Process exit code, 0 on success.
+    """
+    parser = argparse.ArgumentParser(description="U.S. States Game")
+    parser.add_argument(
+        "--show-coordinates",
+        action="store_true",
+        help="log the coordinates of every mouse click on the map",
+    )
+    args = parser.parse_args(argv)
+
+    states = load_states()
+    screen = TurtleScreen()
+    if args.show_coordinates:
+        logging.basicConfig(level=logging.INFO)
+        screen.enable_click_coordinates()
+    try:
+        run_game(screen, states)
+    finally:
+        screen.close()
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())