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.

.gitignore

@@ -0,0 +1,12 @@
+.env
+ui/.env
+
+ui/.next/
+ui/node_modules/
+
+**/__pycache__/
+*.py[cod]
+
+nginx/certs/
+
+backups/