"kitty" theme cursor color generated by matugen is abnormal

It is hoped that the cursor color in the kitty theme template can be changed from "surface" to using the "primary" color of the theme, so that the cursor will be more consistent with the main color of the theme.

**Before**

```
# quickshell/matugen/templates/kitty.conf

cursor {{colors.on_surface.default.hex}}
cursor_text_color {{colors.on_surface_variant.default.hex}}
```

**After**
```
# quickshell/matugen/templates/kitty.conf

cursor {{colors.primary.default.hex}}
cursor_text_color {{colors.background.default.hex}}
```

Open quickshell/matugen/templates/kitty.conf and review the cursor and cursor_text_color template entries shown in the issue. Update them to use the requested theme colors, then generate a kitty theme and verify that the cursor uses the primary color and the cursor text uses the background color.

Written by the indexing model from the issue text.