feat: add how-it-works, supported platforms and FAQ sections to homepage

Enrich the landing page with reassurance/trust content inspired by
competitor downloader sites: a 3-step "how it works" guide, a
supported-platforms grid with a non-affiliation disclaimer, and an
8-question FAQ (with FAQPage JSON-LD) -- all translated across en/fr/es/it.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/app/[locale]/page.tsx

@@ -1,6 +1,9 @@
 import { getTranslations } from 'next-intl/server'
 import { SubmitForm } from '@/components/SubmitForm'
 import { ReassuranceSection } from '@/components/ReassuranceSection'
+import { HowItWorksSection } from '@/components/HowItWorksSection'
+import { SupportedPlatformsSection } from '@/components/SupportedPlatformsSection'
+import { FaqSection } from '@/components/FaqSection'
 
 export default async function Home({
   params,
@@ -32,6 +35,9 @@ export default async function Home({
       </section>
 
       <ReassuranceSection locale={locale} />
+      <HowItWorksSection locale={locale} />
+      <SupportedPlatformsSection locale={locale} />
+      <FaqSection locale={locale} />
     </main>
   )
 }