feat: packages/email — Maizzle v6 + Tailwind CSS v4 HTML email templates

- New @sexy.pivoine.art/email package with @maizzle/framework@6.0.0-15
- Uses @maizzle/tailwindcss (TW v4 preset) with @theme brand tokens
  derived from the frontend's app.css oklch primary color
- LightningCSS automatically lowers oklch/lab to hex for email clients
- Real HTML template files (templates/layouts/main.html, verification.html,
  password-reset.html) — not JS template strings
- PostCSS `from` override so @import "@maizzle/tailwindcss" resolves from
  the email package's own node_modules
- Backend lib/email.ts now calls renderVerification/renderPasswordReset
  instead of inline HTML strings

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

packages/backend/package.json

@@ -20,6 +20,7 @@
     "@fastify/static": "^8.1.1",
     "@pothos/core": "^4.4.0",
     "@pothos/plugin-errors": "^4.2.0",
+    "@sexy.pivoine.art/email": "workspace:*",
     "@sexy.pivoine.art/types": "workspace:*",
     "argon2": "^0.43.0",
     "bullmq": "^5.70.4",

packages/backend/src/lib/email.ts

@@ -1,4 +1,5 @@
 import nodemailer from "nodemailer";
+import { renderVerification, renderPasswordReset } from "@sexy.pivoine.art/email";
 import { mailQueue } from "../queues/index.js";
 
 const transporter = nodemailer.createTransport({
@@ -14,24 +15,15 @@ const transporter = nodemailer.createTransport({
 });
 
 const FROM = process.env.EMAIL_FROM || "noreply@sexy.pivoine.art";
-const BASE_URL = process.env.PUBLIC_URL || "http://localhost:3000";
 
 export async function sendVerification(email: string, token: string): Promise<void> {
-  await transporter.sendMail({
-    from: FROM,
-    to: email,
-    subject: "Verify your email",
-    html: `<p>Click <a href="${BASE_URL}/signup/verify?token=${token}">here</a> to verify your email.</p>`,
-  });
+  const { subject, html } = await renderVerification({ token });
+  await transporter.sendMail({ from: FROM, to: email, subject, html });
 }
 
 export async function sendPasswordReset(email: string, token: string): Promise<void> {
-  await transporter.sendMail({
-    from: FROM,
-    to: email,
-    subject: "Reset your password",
-    html: `<p>Click <a href="${BASE_URL}/password/reset?token=${token}">here</a> to reset your password.</p>`,
-  });
+  const { subject, html } = await renderPasswordReset({ token });
+  await transporter.sendMail({ from: FROM, to: email, subject, html });
 }
 
 const jobOpts = { attempts: 3, backoff: { type: "exponential" as const, delay: 5000 } };