copy(waitlist): drop "no spam, unsubscribe anytime" from demo + marketing

Trim the waitlist microcopy on the standalone demo and the marketing site's
CTA/hero forms to just the value prop, removing the "no spam, unsubscribe
anytime" reassurance line.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01REwWZGkAz1AZUJw8yqxkCN

site/src/components/WaitlistForm.astro

@@ -18,7 +18,7 @@ const {
   source,
   id,
   layout = 'row',
-  microcopy = 'Get early-access invites and the occasional product update — no spam, unsubscribe anytime.',
+  microcopy = 'Get early-access invites and the occasional product update.',
   class: cls = '',
 } = Astro.props;
 

site/src/sections/FinalCta.astro

@@ -13,7 +13,7 @@ import WaitlistForm from '../components/WaitlistForm.astro';
     <WaitlistForm
       source="final"
       class="final-form"
-      microcopy="Get early-access invites and product updates. No spam, unsubscribe anytime."
+      microcopy="Get early-access invites and product updates."
     />
 
     <p class="final-demo">

web/standalone/src/components/WaitlistForm.tsx

@@ -47,8 +47,7 @@ export function WaitlistForm({ source = "standalone" }: { source?: string }) {
       ) : (
         <>
           <p className="mb-4 text-sm text-muted-foreground">
-            Join the waitlist for product updates and your invite — no spam,
-            unsubscribe anytime.
+            Join the waitlist for product updates and your invite.
           </p>
           <form onSubmit={submit} className="flex flex-col gap-2 sm:flex-row">
             <Input