Enhance Code City Apocalypse dashboard with system logs and leaderboard fixes

[BleakNarratives]

This PR enhances the AIRTBench dashboard with several improvements focused on the "Code City Apocalypse" theme and data accuracy:

1. New "📟 System Logs" Tab: Added a stylized terminal view that displays recent agent successes and failures in chronological order, providing a real-time telemetry feel.
2. Leaderboard Fixes: The "Model Success Rates" chart now correctly filters for unique successful challenges per model and includes models with zero successes for a complete comparison.
3. Improved Success Detection: Updated is_event_success to recognize successes in archive datasets by checking for the flag_found_last_attempt_flag.
4. Defensive UI Logic: Fixed a potential KeyError in render_monster_manifest when all challenges have been successfully completed (no monsters remaining).
5. Code Quality: Addressed a ruff linting warning (SIM118) and ensured all changes pass mypy type checking.

Verified visually and with automated Playwright scripts.

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PR created automatically by Jules for task 10833546606512472008 started by @BleakNarratives

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[gemini-code-assist]

Code Review

This pull request introduces a new 'System Logs' tab to the frontend, featuring a terminal-style telemetry view of recent successes and failures. It also updates the leaderboard to display all active models, including those with zero successes, and adds an early return for empty monster data. Review feedback focuses on preventing 'nan' strings from appearing in the UI by suggesting the use of dropna() when identifying unique models and implementing pd.notna() checks for log entries.