[Bug Fix] Honor close_button:true Region prop (was inert)

Region wrapper now carries data-close-button=hover|always plus a
group/toaster anchor. Toast::Close opacity rule extended:
group-data-[close-button=always]/toaster:opacity-100 — when consumer
sets close_button: true on the Region, the X is always visible
(better a11y for touch + cognitive accessibility).

Default stays close_button: false (hover/focus reveal) to match
shadcn sonner. Keyboard a11y unchanged: tab focuses item, focus shows
button, Escape dismisses.

Author: djalmaaraujo

gem/lib/ruby_ui/toast/toast_close.rb

@@ -33,7 +33,7 @@ def default_attrs
           slot: "close",
           action: "click->ruby-ui--toast#dismiss"
         },
-        class: "absolute right-1 top-1 rounded-md p-1 text-foreground/60 opacity-0 transition-opacity hover:text-foreground focus:opacity-100 focus:outline-none focus:ring-1 focus:ring-ring group-hover/toast:opacity-100"
+        class: "absolute right-1 top-1 rounded-md p-1 text-foreground/60 opacity-0 transition-opacity hover:text-foreground focus:opacity-100 focus:outline-none focus:ring-1 focus:ring-ring group-hover/toast:opacity-100 group-data-[close-button=always]/toaster:opacity-100"
       }
     end
   end

gem/lib/ruby_ui/toast/toast_region.rb

@@ -82,6 +82,7 @@ def default_attrs
         aria_live: "polite",
         data: {
           controller: "ruby-ui--toaster",
+          close_button: @close_button ? "always" : "hover",
           position: @position.to_s.tr("_", "-"),
           ruby_ui__toaster_position_value: @position.to_s.tr("_", "-"),
           ruby_ui__toaster_expand_value: @expand.to_s,
@@ -101,7 +102,7 @@ def default_attrs
 
     def region_classes
       <<~CLASSES.tr("\n", " ").squeeze(" ").strip
-        pointer-events-none fixed z-[100] p-4 sm:p-6
+        group/toaster pointer-events-none fixed z-[100] p-4 sm:p-6
         data-[position=top-left]:top-0 data-[position=top-left]:left-0
         data-[position=top-center]:top-0 data-[position=top-center]:left-1/2 data-[position=top-center]:-translate-x-1/2
         data-[position=top-right]:top-0 data-[position=top-right]:right-0