test: streamline examples with quit texts

Improve some examples to provide visual feedback, i.e. for the button
exmample, with fixes to make them compilable with the `Scrollable`
element changes.

examples/styles/palette.zig

@@ -56,7 +56,6 @@ pub fn main() !void {
 
     var box = try App.Container.init(allocator, .{
         .layout = .{ .direction = .horizontal },
-        .min_size = .{ .cols = 3 * std.meta.fields(zterm.Color).len }, // ensure enough columns to render all colors -> scrollable otherwise
     }, .{});
     defer box.deinit();
 
@@ -64,7 +63,7 @@ pub fn main() !void {
         if (comptime field.value == 0) continue; // zterm.Color.default == 0 -> skip
         try box.append(try App.Container.init(allocator, .{ .rectangle = .{ .fill = @enumFromInt(field.value) } }, .{}));
     }
-    var scrollable: App.Scrollable = .init(box);
+    var scrollable: App.Scrollable = .init(box, .{ .cols = 3 * std.meta.fields(zterm.Color).len }); // ensure enough columns to render all colors -> scrollable otherwise
     try container.append(try App.Container.init(allocator, .{}, scrollable.element()));
 
     try app.start();