feat: admin panel - Settings, Categories, Payment Wallets, Seed/Clear data, User Balances

- Settings page: bot token (masked), admin IDs, commission config, WireGuard status
- Categories page: CRUD with product count, delete guard
- Payment Wallets page: commission wallets display, toggle, percentage
- Users page: balance adjustment form (total_balance / bonus_balance) with audit log
- Seed & Reset page: seed demo data (5 users, 10 products, 5 wallets, 5 purchases)
  and clear all data button with confirmation
- Dashboard: flash messages for seed/clear success
- Fixed seed.js: use dynamic IDs instead of hardcoded to avoid FK violations
- Fixed seed.js: clear all tables before seeding to avoid UNIQUE constraints

src/admin/views/paymentWallets.js

@@ -0,0 +1,32 @@
+import { layout } from './layout.js';
+
+export function renderPaymentWallets(data) {
+  const walletRows = Object.entries(data.wallets).map(([type, addr]) =>
+    `<tr>
+      <td><strong>${type}</strong></td>
+      <td><code>${escapeHtml(addr || 'Not set')}</code></td>
+    </tr>`
+  ).join('');
+
+  const content = `
+    <div class="detail-card">
+      <h2>Commission Status</h2>
+      <p><strong>Commission:</strong> <span class="badge badge-${data.commissionEnabled ? 'active' : 'banned'}">${data.commissionEnabled ? 'ON' : 'OFF'}</span></p>
+      <p><strong>Percentage:</strong> ${data.commissionPercent}%</p>
+    </div>
+
+    <div class="detail-card">
+      <h2>Commission Wallet Addresses</h2>
+      <p class="muted">These are the shop's payment wallets. Edit them in the <code>.env</code> file.</p>
+      <table>
+        <thead><tr><th>Currency</th><th>Address</th></tr></thead>
+        <tbody>${walletRows}</tbody>
+      </table>
+    </div>
+  `;
+  return layout('Payment Wallets', content, 'payment-wallets');
+}
+
+function escapeHtml(str) {
+  return String(str).replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;');
+}