feat: add subscription service — user auth, Stripe billing, API keys, dashboard

- NextAuth v5 with email+password credentials, JWT sessions
- Registration, login, email verification, password reset flows
- Stripe integration: Free (15/day), Starter ($5/1k/mo), Pro ($20/100k/mo)
- API key management (cb_ prefix) with hash-based validation
- Dashboard with generations history, settings, billing management
- Rate limiting: Redis daily counter (free), DB monthly (paid)
- Generate route auth: Bearer API key + session, anonymous allowed
- Worker userId propagation for generation history
- Pricing section on landing page, auth-aware navbar
- Middleware with route protection, CORS for codeboard.vectry.tech
- Docker env vars for auth, Stripe, email (smtp.migadu.com)

apps/web/src/lib/email.ts

@@ -0,0 +1,36 @@
+import nodemailer from "nodemailer";
+
+interface SendEmailOptions {
+  to: string;
+  subject: string;
+  html: string;
+}
+
+export async function sendEmail({ to, subject, html }: SendEmailOptions) {
+  const password = process.env.EMAIL_PASSWORD;
+
+  if (!password) {
+    console.warn(
+      "[email] EMAIL_PASSWORD not set — skipping email send to:",
+      to
+    );
+    return;
+  }
+
+  const transporter = nodemailer.createTransport({
+    host: "smtp.migadu.com",
+    port: 465,
+    secure: true,
+    auth: {
+      user: "hunter@repi.fun",
+      pass: password,
+    },
+  });
+
+  await transporter.sendMail({
+    from: "CodeBoard <hunter@repi.fun>",
+    to,
+    subject,
+    html,
+  });
+}