refactor(frontend): point frontend at rust stealth-api

frontend/src/services/walletService.js

@@ -1,5 +1,9 @@
 export const analyzeWallet = async (descriptor) => {
-  const res = await fetch(`/api/wallet/scan?descriptor=${encodeURIComponent(descriptor)}`)
+  const res = await fetch('/api/wallet/scan', {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify({ descriptor }),
+  })
   if (!res.ok) throw new Error('Analysis failed')
   return res.json()
 }

frontend/vite.config.js

@@ -5,7 +5,7 @@ export default defineConfig({
   plugins: [react()],
   server: {
     proxy: {
-      '/api': 'http://localhost:8080'
+      '/api': 'http://localhost:20899'
     }
   }
 })