feat: SaaS closed beta waitlist section

Gauges B2B interest in a commercial tier built on top of Greywall's
open-source core. The plugin SDK angle leans into what people have
actually been asking for: extending Greyproxy with custom heuristics,
Model Council, and token-saving MITM plugins. Web3forms handles signup.

Core stays free and open source; the new tier rides on top.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/page.tsx

@@ -10,6 +10,7 @@ import { Layers } from '@/components/layers'
 import { Observability } from '@/components/observability'
 import { Control } from '@/components/control'
 import { Comparison } from '@/components/comparison'
+import { Waitlist } from '@/components/waitlist'
 import { About } from '@/components/about'
 import { FAQ } from '@/components/faq'
 import { Footer } from '@/components/footer'
@@ -27,6 +28,7 @@ export default function Home() {
         <Control />
         <Comparison />
         <GettingStarted />
+        <Waitlist />
         <About />
         <FAQ />
         <Footer />