feat(storage): save HD to ~/.wallet-generator/hdwallet and single to ~/.wallet-generator/single

frontend/electron/main.cjs

@@ -10,10 +10,19 @@ const VITE_PORT = 5173
 let mainWindow = null
 
 // ── Wallet storage directory ───────────────────────────────────────────────────
-const WALLET_DIR = path.join(os.homedir(), '.wallet-generator', 'wallet')
+const WALLET_ROOT_DIR = path.join(os.homedir(), '.wallet-generator')
+const WALLET_DIRS = {
+  hd: path.join(WALLET_ROOT_DIR, 'hdwallet'),
+  single: path.join(WALLET_ROOT_DIR, 'single'),
+}
 
-function ensureWalletDir() {
-  fs.mkdirSync(WALLET_DIR, { recursive: true })
+function ensureWalletDir(kind) {
+  const walletDir = WALLET_DIRS[kind]
+  if (!walletDir) {
+    throw new Error(`Unsupported wallet kind: '${kind}'. Use 'hd' or 'single'.`)
+  }
+  fs.mkdirSync(walletDir, { recursive: true })
+  return walletDir
 }
 
 // ── Resolve Python executable ──────────────────────────────────────────────────
@@ -54,16 +63,16 @@ ipcMain.handle('p2wpkh',      (_, args) => callPython('p2wpkh',      args))
 ipcMain.handle('p2tr',        (_, args) => callPython('p2tr',        args))
 ipcMain.handle('single-encrypt', (_, args) => callPython('single_encrypt', args))
 
-ipcMain.handle('save-wallet', (_, { filename, data }) => {
-  ensureWalletDir()
-  const filePath = path.join(WALLET_DIR, filename)
+ipcMain.handle('save-wallet', (_, { filename, data, kind }) => {
+  const walletDir = ensureWalletDir(kind)
+  const filePath = path.join(walletDir, filename)
   fs.writeFileSync(filePath, JSON.stringify(data, null, 2), 'utf-8')
   return filePath
 })
 
 ipcMain.handle('get-wallet-dir', () => {
-  ensureWalletDir()
-  return WALLET_DIR
+  fs.mkdirSync(WALLET_ROOT_DIR, { recursive: true })
+  return WALLET_ROOT_DIR
 })
 
 // ── Create window ──────────────────────────────────────────────────────────────

frontend/electron/preload.cjs

@@ -10,6 +10,6 @@ contextBridge.exposeInMainWorld('electronAPI', {
   p2wpkh:       (args) => ipcRenderer.invoke('p2wpkh',      args),
   p2tr:         (args) => ipcRenderer.invoke('p2tr',        args),
   singleEncrypt:(args) => ipcRenderer.invoke('single-encrypt', args),
-  saveWallet:   (filename, data) => ipcRenderer.invoke('save-wallet', { filename, data }),
+  saveWallet:   (filename, data, kind) => ipcRenderer.invoke('save-wallet', { filename, data, kind }),
   getWalletDir: ()     => ipcRenderer.invoke('get-wallet-dir'),
 })

frontend/src/components/HDWallet.jsx

@@ -52,7 +52,7 @@ export default function HDWallet() {
         data = await window.electronAPI.hdEncrypt({ wallet, password: savePassword })
       }
       const filename = `wallet_${form.network}_${form.bip_type}_${Date.now()}.json`
-      const savedPath = await window.electronAPI.saveWallet(filename, data)
+      const savedPath = await window.electronAPI.saveWallet(filename, data, 'hd')
       const encrypted = savePassword ? ' (encrypted)' : ''
       setSaveMsg(`Saved${encrypted}: ${savedPath}`)
     } catch (e) {

frontend/src/components/SingleAddress.jsx

@@ -60,7 +60,7 @@ export default function SingleAddress({ initialTab = 'p2pkh' }) {
         data = await window.electronAPI.singleEncrypt({ wallet: result, password: savePassword })
       }
       const name = filename.trim().endsWith('.json') ? filename.trim() : `${filename.trim()}.json`
-      const savedPath = await window.electronAPI.saveWallet(name, data)
+      const savedPath = await window.electronAPI.saveWallet(name, data, 'single')
       setSaveMsg(savePassword.trim() ? `Saved (encrypted): ${savedPath}` : `Saved: ${savedPath}`)
     } catch (e) {
       setSaveMsg('Error: ' + e.message)
@@ -141,7 +141,7 @@ export default function SingleAddress({ initialTab = 'p2pkh' }) {
                   value={filename}
                   onChange={e => setFilename(e.target.value)}
                 />
-                <span className="form-hint">.json · saved to ~/.wallet-generator/wallet/</span>
+                <span className="form-hint">.json · saved to ~/.wallet-generator/single/</span>
               </div>
               <div className="form-group">
                 <label className="form-label">Encryption password (optional)</label>