config: tweak.surface-bit-depth now defaults to 'auto'

When set to 'auto', use 10-bit surfaces if gamma-correct blending is
enabled, and 8-bit surfaces otherwise.

Note that we may still fallback to 8-bit surfaces (without disabling
gamma-correct blending) if the compositor does not support 10-bit
surfaces.

Closes #2082

CHANGELOG.md

@@ -84,6 +84,7 @@
   - paper-color
   - selenized
   - solarized
+* `auto` to the `tweak.surface-bit-depth` option.
 
 [2025]: https://codeberg.org/dnkl/foot/issues/2025
 
@@ -92,6 +93,9 @@
 
 * `cursor.color` moved to `colors.cursor`.
 * `gamma-correct-blending` now defaults to `no` instead of `yes`.
+* `tweak.surface-bit-depth` default value changed to `auto`; uses
+  10-bit surfaces when `gamma-correct-blending=yes`, and 8-bit
+  surfaces otherwise.
 
 
 ### Deprecated
@@ -101,6 +105,12 @@
 
 ### Removed
 ### Fixed
+
+* Inaccurate colors when `gamma-correct-blending=yes` ([#2082][2082]).
+
+[2082]: https://codeberg.org/dnkl/foot/issues/2082
+
+
 ### Security
 ### Contributors