refactor: replace fetch() calls with window.electronAPI in React components

- HDWallet, SingleAddress, DecryptWallet now call window.electronAPI.*
- Remove Vite proxy (no more HTTP backend)

frontend/src/components/DecryptWallet.jsx

@@ -1,8 +1,6 @@
 import { useState, useRef } from 'react'
 import CopyButton from './CopyButton'
 
-const API = ''
-
 export default function DecryptWallet() {
   const [password, setPassword] = useState('')
   const [wallet, setWallet] = useState(null)
@@ -37,13 +35,7 @@ export default function DecryptWallet() {
     setError(null)
     setResult(null)
     try {
-      const res = await fetch(`${API}/api/hd/decrypt`, {
-        method: 'POST',
-        headers: { 'Content-Type': 'application/json' },
-        body: JSON.stringify({ wallet, password }),
-      })
-      if (!res.ok) throw new Error((await res.json()).detail)
-      setResult(await res.json())
+      setResult(await window.electronAPI.hdDecrypt({ wallet, password }))
       setSeedVisible(false)
     } catch (e) {
       setError(e.message)

frontend/src/components/HDWallet.jsx

@@ -1,8 +1,6 @@
 import { useState } from 'react'
 import CopyButton from './CopyButton'
 
-const API = ''
-
 export default function HDWallet() {
   const [form, setForm] = useState({
     network: 'mainnet',
@@ -28,23 +26,15 @@ export default function HDWallet() {
     setWallet(null)
     setSeedVisible(false)
     try {
-      const res = await fetch(`${API}/api/hd/generate`, {
-        method: 'POST',
-        headers: { 'Content-Type': 'application/json' },
-        body: JSON.stringify({
+      const data = await window.electronAPI.hdGenerate({
         network: form.network,
         bip_type: form.bip_type,
         mnemonic: form.mnemonic.trim() || null,
         passphrase: form.passphrase,
         account: parseInt(form.account) || 0,
         num_addresses: parseInt(form.num_addresses) || 5,
-        }),
       })
-      if (!res.ok) {
-        const e = await res.json()
-        throw new Error(e.detail || 'API error')
-      }
-      setWallet(await res.json())
+      setWallet(data)
     } catch (e) {
       setError(e.message)
     } finally {
@@ -59,13 +49,7 @@ export default function HDWallet() {
     try {
       let data = wallet
       if (savePassword.trim()) {
-        const res = await fetch(`${API}/api/hd/encrypt`, {
-          method: 'POST',
-          headers: { 'Content-Type': 'application/json' },
-          body: JSON.stringify({ wallet, password: savePassword }),
-        })
-        if (!res.ok) throw new Error((await res.json()).detail)
-        data = await res.json()
+        data = await window.electronAPI.hdEncrypt({ wallet, password: savePassword })
       }
       const blob = new Blob([JSON.stringify(data, null, 2)], { type: 'application/json' })
       const url = URL.createObjectURL(blob)
@@ -89,7 +73,6 @@ export default function HDWallet() {
       <div className="page-title">HD Wallet</div>
       <div className="page-subtitle">BIP-32/39 · Hierarchical deterministic wallet</div>
 
-      {/* ── Configuration ── */}
       <div className="card">
         <div className="card-title">Configuration</div>
         <div className="form-grid">
@@ -141,7 +124,6 @@ export default function HDWallet() {
 
       {wallet && (
         <>
-          {/* ── Seed phrase ── */}
           <div className="card">
             <div className="card-title" style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center' }}>
               <span>Seed Phrase</span>
@@ -161,7 +143,6 @@ export default function HDWallet() {
             </div>
           </div>
 
-          {/* ── Keystore ── */}
           <div className="card">
             <div className="card-title">Keystore</div>
             {[
@@ -178,7 +159,6 @@ export default function HDWallet() {
             ))}
           </div>
 
-          {/* ── Addresses ── */}
           <div className="card">
             <div className="card-title">Receiving Addresses</div>
             <table className="addr-table">
@@ -212,7 +192,6 @@ export default function HDWallet() {
             </table>
           </div>
 
-          {/* ── Save ── */}
           <div className="card">
             <div className="card-title">Save Wallet</div>
             <div className="form-grid" style={{ marginBottom: 12 }}>

frontend/src/components/SingleAddress.jsx

@@ -1,8 +1,6 @@
 import { useState } from 'react'
 import CopyButton from './CopyButton'
 
-const API = ''
-
 const TABS = [
   { id: 'p2pkh',  label: 'P2PKH',  desc: 'Legacy · starts with 1 / m' },
   { id: 'p2wpkh', label: 'P2WPKH', desc: 'Native SegWit · bc1q / tb1q' },
@@ -26,17 +24,12 @@ export default function SingleAddress({ initialTab = 'p2pkh' }) {
     setError(null)
     setResult(null)
     try {
-      let body = { network }
-      if (tab === 'p2sh') body = { ...body, m, n, compressed }
-      else if (tab !== 'p2tr') body = { ...body, compressed }
+      let args = { network }
+      if (tab === 'p2sh') args = { ...args, m, n, compressed }
+      else if (tab !== 'p2tr') args = { ...args, compressed }
 
-      const res = await fetch(`${API}/api/${tab}`, {
-        method: 'POST',
-        headers: { 'Content-Type': 'application/json' },
-        body: JSON.stringify(body),
-      })
-      if (!res.ok) throw new Error((await res.json()).detail)
-      setResult(await res.json())
+      const fn = window.electronAPI[tab === 'p2pkh' ? 'p2pkh' : tab === 'p2wpkh' ? 'p2wpkh' : tab === 'p2tr' ? 'p2tr' : tab === 'p2pk' ? 'p2pk' : 'p2sh']
+      setResult(await fn(args))
     } catch (e) {
       setError(e.message)
     } finally {

frontend/vite.config.js

@@ -5,11 +5,5 @@ export default defineConfig({
   plugins: [react()],
   server: {
     port: 5173,
-    proxy: {
-      '/api': {
-        target: 'http://localhost:8000',
-        changeOrigin: true,
-      },
-    },
   },
 })