fix toast display and auto-dismiss

- Wrap toast message in span for proper text rendering
- Use setTimeout instead of mosis.timer for auto-dismiss
- Remove unsupported CSS animation property
- Add explicit color to toast variants
- Change px to dp units for RmlUi compatibility

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/main/assets/apps/shell/shell.lua

@@ -227,14 +227,13 @@ function showToast(message, type)
         class = "toast toast-warning"
     end
 
-    -- Add toast element
-    local toast_html = '<div class="' .. class .. '">' .. message .. '</div>'
-    container.inner_rml = container.inner_rml .. toast_html
+    -- Clear existing toasts and add new one
+    local toast_html = '<div class="' .. class .. '"><span>' .. message .. '</span></div>'
+    container.inner_rml = toast_html
 
-    -- Auto-remove after 3 seconds (would need timer API)
-    if mosis and mosis.timer then
-        mosis.timer.setTimeout(function()
-            -- Remove first toast
+    -- Auto-remove after 3 seconds
+    if setTimeout then
+        setTimeout(function()
             container.inner_rml = ""
         end, 3000)
     end