fix(preventivo): slide deck 100vh — nessuno scroll di pagina

- ProposalDeck: outer div h-screen overflow-hidden, content wrapper h-full
- Rimosso il div interno ridondante min-h-screen
- useEffect blocca body overflow mentre la deck è aperta
- Tutti i 20 componenti slide: min-h-screen → h-full

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

src/components/public/proposal/sections/ScopeSection.tsx

@@ -5,7 +5,7 @@ type Props = { scope: ProposalContent["scope"] };
 
 export function ScopeSection({ scope }: Props) {
   return (
-    <div className="min-h-screen flex items-center px-16 py-24">
+    <div className="h-full flex items-center px-16 py-24">
       <div className="grid grid-cols-2 gap-12 w-full">
         {/* Scope */}
         <div className="border border-primary/20 bg-primary/5 rounded-xl p-8 space-y-4">