Build 25148241

- Improved main spiral rendering performance. The spiral recalculated its screen mapping once for every point on the curve; it now does this once per frame. Sessions with many visible curves should be noticeably smoother.
- The game now runs at a reduced frame rate while in the background, and returns to your chosen rate as soon as the window is focused again. The frame rate is checked continuously rather than relying on a single notification, so the game cannot get stuck at the reduced rate.
- Added a frame rate and a spiral refresh rate setting so you can choose how much of your machine the game uses.
- Added a Fit button to the menu bar that reframes the main spiral to the current curve.
- Main Spiral Scale now follows a growing distance at a usable speed. It was easing so slowly that the view could lag far behind the spiral it was meant to be tracking.
- Create Backup now works when saving has been blocked. Save writes stop for the rest of a session when the game cannot verify its startup backup — which is exactly when you would want a backup. It now captures your retained save data instead of the empty objects the blocked session is running on.
- Save recovery now shows why a restore was rejected, rather than only that it failed.
- Auto Prestige can now be set to a threshold of 0. Zero was previously indistinguishable from "not set", so it was ignored.