Add Cue n Woo crash check qualifiers

[KyleHerndon]

Summary

• Add a Qualifiers staging division to the bundled Cue n Woo ruleset strategy config.
• Schedule exactly two self-play crash-check episodes per qualifying entrant.
• Promote qualifiers directly to the competition division only when their crash-check round score is greater than zero.
• Disqualify qualifiers when no crash-check episode completes, or when their completed crash-check round score is zero or negative.
• Disqualify Competition champions at round completion when their average score for the round is zero or negative.
• Leave the competition division on leaderboard_neighbors with min_episodes_per_entrant: 4.
• Schedule Cue n Woo rounds every 15 minutes.
• Allow commissioner episode cancellation windows up to 10 minutes so 10-minute Cue n Woo rounds are not cut off at 5 minutes.
• Add on_round_complete as the explicit transition hook, while preserving on_episode_complete as a legacy alias for existing configs.

Validation

• PASS: PYTHONDONTWRITEBYTECODE=1 PYTHONPATH=/tmp/commissioners-cue-n-woo-qualifiers-pr /tmp/commissioners-cue-n-woo/.venv/bin/python -m pytest tests/test_commissioner_strategies.py tests/test_commissioner_websocket.py::test_configured_episode_timeout_reads_round_timeout_seconds tests/test_commissioner_websocket.py::test_episode_duration_limit_doubles_timeout_and_caps_at_ten_minutes tests/test_commissioner_websocket.py::test_episode_duration_limit_allows_ten_minute_round_timeout -q (52 passed in 0.53s)
• PASS: PYTHONDONTWRITEBYTECODE=1 PYTHONPATH=/tmp/commissioners-cue-n-woo-qualifiers-pr /tmp/commissioners-cue-n-woo/.venv/bin/python -m py_compile commissioners/common/ruleset_strategy/config.py commissioners/common/server.py
• PASS: git diff --check
• Lint: no lint command or ruff config is present in pyproject.toml.