feat(Newsletter): add newsletter signup section with framed card layout

Cream card (bg-[#f8f3ec], rounded-xl) inside section padding of 80px.
Left copy column has fixed w-[38.25rem] (612px) with icon (-rotate-4)
and Lora heading; right form column is flex-1 with email input +
orange submit button side by side, privacy note below. Input and button
share items-stretch so they align to equal height.

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

app/page.tsx

@@ -3,6 +3,7 @@ import { Divider } from "./components/Divider";
 import { Tools } from "./components/Tools";
 import { Blog } from "./components/Blog";
 import { About } from "./components/About";
+import { Newsletter } from "./components/Newsletter";
 
 export default function Home() {
   return (
@@ -12,6 +13,7 @@ export default function Home() {
       <Tools />
       <Blog />
       <About />
+      <Newsletter />
     </main>
   );
 }