Closes https://github.com/KittyCAD/engine/issues/3494. Thanks to @nadr0 for helping on the JS side.
If users set their units, the grid will stop auto scaling, and instead will be set to 10 of whatever unit they used.
If users set their units, and those units are metric, then it'll include a scale bar (see screenshot). Imperial units won't have that bar.
This behaviour is configurable via settings.
## Limitations
- The scale bar below the grid cannot be disabled in metric units, and cannot be enabled in imperial units
<img width="1690" alt="Screenshot 2025-06-05 at 7 51 41 PM" src="https://github.com/user-attachments/assets/c597087c-f96d-4c30-95f4-b3d8ba2b5567" />
* Add libm dependency
* Change to use libm for trig functions
* Remove redactions for floating point
* Update output
* Use clippy to prevent stdlib math sneaking back in
---------
Co-authored-by: Adam Chalmers <adam.chalmers@zoo.dev>
* Change to use deterministic artifact graph
* Update output to use the new order
* Fix to clear everything when scene is cleared
* Fix lots
* Update artifact graph output for the last time
* Delete unused sorting code
* Remove unneeded cfg
* Fix to preserve top-level artifacts when there's an error
* Update output after error fix
* Add better doc comments
* Remove duplicate global operations
* Update comments
* Update ignored tests that were flaky
* Update graph for new samples after rebase
* Fix test assertion message
