style: Adjust hover color for GhostButtonTheme

This commit updates the hover effect for ghost buttons to improve visual feedback.

The background color on hover has been changed from `Colors.gray[100]` to `Colors.gray[200]` in the light theme. This makes the hover state more distinct and noticeable for the user. Additionally, the logic has been simplified to only apply a custom decoration when the button is hovered, falling back to the default otherwise.

Author: Lukas Gundermann

lib/screens/widgets/overrides/button_themes.dart

@@ -72,19 +72,12 @@ class ButtonThemes extends StatelessWidget {
         child: ComponentTheme(
           data: GhostButtonTheme(
             decoration: (context, states, defaultDecoration) {
-              if (states.contains(WidgetState.disabled)) {
-                return defaultDecoration.copyWithIfBoxDecoration(
-                  color: Colors.transparent,
-                );
-              } else if (states.contains(WidgetState.hovered)) {
-                return defaultDecoration.copyWithIfBoxDecoration(
-                  color: isDark ? Colors.gray[600] : Colors.gray[100],
-                );
-              } else {
+              if (states.contains(WidgetState.hovered)) {
                 return defaultDecoration.copyWithIfBoxDecoration(
-                  color: Colors.transparent,
+                  color: isDark ? Colors.gray[600] : Colors.gray[200],
                 );
               }
+              return defaultDecoration;
             },
             textStyle: (context, states, defaultTextStyle) {
               if (states.contains(WidgetState.disabled)) {