Fork xmrcheckout for Wownero (WOW)

Minimal changes from upstream xmrcheckout to support Wownero:
- Rate provider: Nonlogs WOW-BTC via Kraken BTC/USD
- Subaddress derivation: Wownero network byte overrides (53/63/54)
- Payment URI scheme: wownero:
- Dockerfile: Wownero binaries from Codeberg
- Display text: Monero→Wownero, XMR→WOW throughout UI
- Default daemon: 192.168.88.235:34568
- Added wownero-logo.svg

File and folder structure kept identical to upstream for easy sync.

ui/app/(app)/welcome/page.tsx

@@ -0,0 +1,15 @@
+import type { Metadata } from "next";
+import { cookies } from "next/headers";
+import { redirect } from "next/navigation";
+
+export const metadata: Metadata = {
+  title: "Welcome",
+};
+
+export default async function WelcomePage() {
+  const session = (await cookies()).get("wowcheckout_session")?.value;
+  if (!session) {
+    redirect("/?login=1");
+  }
+  redirect("/dashboard");
+}