Replace static Hello World with KenJim Technologies React app

- Vite + React frontend: hero, services grid, contact form
- Express + nodemailer backend for contact form → kenji@kenjim.com
- Multi-stage Docker builds; nginx inside frontend proxies /api to backend
- SMTP config via .env (see .env.example)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.env.example

@@ -0,0 +1,11 @@
+# Copy to .env and fill in your SMTP credentials
+# Common options:
+#   Gmail:   SMTP_HOST=smtp.gmail.com  SMTP_PORT=587  SMTP_SECURE=false
+#   Office365: SMTP_HOST=smtp.office365.com  SMTP_PORT=587  SMTP_SECURE=false
+
+SMTP_HOST=smtp.gmail.com
+SMTP_PORT=587
+SMTP_SECURE=false
+SMTP_USER=your-sending-address@gmail.com
+SMTP_PASS=your-app-password
+CONTACT_TO=kenji@kenjim.com