feat: add noStrudel Nostr client with NIP-07 iframe proxy support

Added nostrudel.ninja as a web-only app in Marketplace (community category).
Configured nginx reverse proxy at /ext/nostrudel/ with NIP-07 provider
injection in both HTTP and HTTPS blocks.

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

neode-ui/public/assets/img/app-icons/nostrudel.svg

@@ -0,0 +1,7 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 64 64" fill="none">
+  <rect width="64" height="64" rx="14" fill="#7B3FE4"/>
+  <circle cx="32" cy="28" r="10" stroke="white" stroke-width="3" fill="none"/>
+  <path d="M22 44c0-5.523 4.477-10 10-10s10 4.477 10 10" stroke="white" stroke-width="3" stroke-linecap="round" fill="none"/>
+  <circle cx="46" cy="18" r="4" fill="#E8B4F8"/>
+  <path d="M46 22v6M46 28l4 4M46 28l-4 4" stroke="#E8B4F8" stroke-width="2" stroke-linecap="round"/>
+</svg>