Sign-up goes straight to onboarding; refresh CLAUDE.md

Email verification is no longer enforced (see backend), and sign-up now
auto-signs-in, so route to clinic onboarding instead of /verify-email.
Update CLAUDE.md: the app now talks to ../backend (auth + patient API),
route protection via proxy.ts, and build/type-check guidance.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/app/(auth)/signup/page.tsx

@@ -47,7 +47,10 @@ export default function SignupPage() {
       setSubmitting(false);
       return;
     }
-    router.push(`/verify-email?email=${encodeURIComponent(email.trim())}`);
+    // Email verification isn't enforced yet (see backend auth config), so the
+    // user is signed in on sign-up — go straight to clinic onboarding. A
+    // verification email is still sent for when verification is re-enabled.
+    router.push("/");
   };
 
   return (