Stability, precision, and cleanup — System.Execute Steam update #1405029

This update focuses on under-the-hood fixes found during a full codebase audit. No new features, but a lot of things work better now. Bug Fixes Fixed achievement tracking for high-value milestones (10P+ FLOPS, 10Q+ FLOPS/s) that could silently fail to trigger due to number precision limits Fixed the export fallback overwriting copied save data before you could copy it Fixed the optimization panel toggle not responding to clicks on unlocked nodes Fixed a save rename issue where pressing Enter could save the name twice Fixed the Escape key occasionally crashing when certain UI panels hadn't loaded yet Void protocol windows now survive a save and reload instead of resetting their timer Removed a checksum warning that could falsely flag valid saves as corrupted Performance Leaderboard credits page now loads all categories in parallel instead of one at a time Reduced unnecessary per-frame che...