feat: scaffold Antonym fashion store

Anonymous Bitcoin-only fashion e-commerce with:
- Vue 3 + Tailwind 4 frontend with glassmorphism dark/light design system
- Express 5 + SQLite backend with BTCPay Server integration
- Nostr identity (NIP-07/keypair) for anonymous purchase tracking
- ChaCha20-Poly1305 encrypted shipping addresses
- Admin panel with order/product/stock management
- SVG logo splash animation with clip-path reveal
- 5 seeded products across 4 categories

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

server/lib/mailer.ts

@@ -0,0 +1,24 @@
+import nodemailer from 'nodemailer'
+
+let transporter: nodemailer.Transporter | null = null
+
+function getTransporter(): nodemailer.Transporter | null {
+  if (transporter) return transporter
+  const host = process.env.SMTP_HOST
+  if (!host) return null
+  transporter = nodemailer.createTransport({ host, port: Number(process.env.SMTP_PORT) || 587, secure: Number(process.env.SMTP_PORT) === 465, auth: { user: process.env.SMTP_USER, pass: process.env.SMTP_PASS } })
+  return transporter
+}
+
+export async function sendOrderConfirmation(email: string, orderId: string, totalSats: number): Promise<void> {
+  const t = getTransporter()
+  if (!t) return
+  await t.sendMail({ from: process.env.SMTP_FROM || 'orders@antonym.fashion', to: email, subject: `Order Confirmed - ${orderId}`, text: `Your order ${orderId} for ${totalSats.toLocaleString()} sats has been confirmed.\n\nTrack your order: ${process.env.SITE_URL || 'http://localhost:3333'}/order/${orderId}` })
+}
+
+export async function sendStatusUpdate(email: string, orderId: string, status: string, note?: string): Promise<void> {
+  const t = getTransporter()
+  if (!t) return
+  const noteText = note ? `\n\nNote: ${note}` : ''
+  await t.sendMail({ from: process.env.SMTP_FROM || 'orders@antonym.fashion', to: email, subject: `Order ${orderId} - ${status.charAt(0).toUpperCase() + status.slice(1)}`, text: `Your order ${orderId} status has been updated to: ${status}${noteText}\n\nTrack your order: ${process.env.SITE_URL || 'http://localhost:3333'}/order/${orderId}` })
+}