Run qualifier stages through episode complete

[KyleHerndon]

Summary

• add policy membership events to episode_completed_response and emit them from the /round websocket after episode_result/episode_failed
• schedule all current qualifier stages simultaneously for ruleset strategy staging divisions
• report qualifier stage progress as n/m stages completed, list completed/pending stages in notes, and promote after all stages complete
• track effective membership state inside the ruleset commissioner during a round, so later episode-complete decisions use membership events already emitted by that commissioner instead of only the original round_start snapshot
• keep disqualifying updates terminal through that generic effective-membership state, so a later already-running stage cannot requalify or promote the same round/member
• extract effective membership folding and qualifier stage progress into ruleset_strategy/round_state.py helpers, including explicit duplicate / failed / progressed / promoted transition kinds, to keep RulesetStrategyCommissioner.on_episode_complete focused on orchestration
• update Among Them config/tests and terminal-failure regression tests to exercise the real ruleset commissioner path

Validation

• PASS: .venv/bin/python -m pytest tests/test_commissioner_strategies.py -q (38 passed)
• PASS: .venv/bin/python -m pytest tests/test_commissioner_strategies.py::test_ruleset_strategy_parallel_qualifier_crash_failure_blocks_later_score_success tests/test_commissioner_strategies.py::test_ruleset_strategy_parallel_qualifier_score_failure_blocks_later_crash_success tests/test_commissioner_strategies.py::test_ruleset_strategy_among_them_config_targets_daily_competition_division tests/test_commissioner_strategies.py::test_ruleset_strategy_among_them_config_first_qualifier_stage_advances_to_score_gate -q (4 passed)
• PASS: uvx ruff check commissioners/common/protocol.py commissioners/common/server.py commissioners/common/ruleset_strategy/commissioner.py commissioners/common/ruleset_strategy/round_state.py tests/test_commissioner_strategies.py tests/test_commissioner_websocket.py
• PASS: uvx ruff check commissioners/common/commissioners.py --ignore F401,E402
• PASS: .venv/bin/python -m compileall -q commissioners tests
• PASS: git diff --check
• NOTE: broad local websocket pytest commands did not return a result in this environment; the direct commissioner regression tests cover the terminal-failure ordering logic.