fix: widget embed — full-width support + one-liner script tags via hosted loader

- Standalone page: ?width=full removes max-w-lg container constraint
- iframeSnippet: passes &width=full to URL when 100% width selected
- public/widget-loader.js: hosted script, reads data-* attrs, no inline code needed
  - data-mode="floating" → styled FAB button bottom-right
  - data-mode="trigger"  → listens for .hotelsync-book class clicks
  - Proper modal with close button and backdrop click
- Code tab snippets for floating/trigger are now single <script src> lines

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/pages/BookingWidgetStandalonePage.tsx

@@ -74,9 +74,11 @@ export function BookingWidgetStandalonePage() {
       .catch(() => {})
   }, [slug])
 
+  const isFullWidth = searchParams.get('width') === 'full'
+
   return (
-    <div className="min-h-screen bg-slate-50 flex items-start justify-center py-6 px-3">
-      <div className="w-full max-w-lg">
+    <div className={isFullWidth ? 'min-h-screen bg-slate-50' : 'min-h-screen bg-slate-50 flex items-start justify-center py-6 px-3'}>
+      <div className={isFullWidth ? 'w-full' : 'w-full max-w-lg'}>
         <WidgetPreview
           settings={settings}
           slug={slug}