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/email/src/index.ts

@@ -0,0 +1,25 @@
+import { renderTemplate } from "./render.js";
+
+const BASE_URL = process.env.PUBLIC_URL ?? "https://sexy.pivoine.art";
+
+export async function renderVerification(data: {
+  token: string;
+}): Promise<{ subject: string; html: string }> {
+  return {
+    subject: "Verify your email address — sexy.pivoine.art",
+    html: await renderTemplate("verification", {
+      url: `${BASE_URL}/signup/verify?token=${data.token}`,
+    }),
+  };
+}
+
+export async function renderPasswordReset(data: {
+  token: string;
+}): Promise<{ subject: string; html: string }> {
+  return {
+    subject: "Reset your password — sexy.pivoine.art",
+    html: await renderTemplate("password-reset", {
+      url: `${BASE_URL}/password/reset?token=${data.token}`,
+    }),
+  };
+}

packages/email/src/render.ts

@@ -0,0 +1,43 @@
+import { readFile } from "node:fs/promises";
+import path from "node:path";
+
+// Templates live at packages/email/templates/
+// At runtime (dist/render.js), __dirname is packages/email/dist/
+const PKG_ROOT = path.join(__dirname, "..");
+const TEMPLATES_ROOT = path.join(PKG_ROOT, "templates");
+const BASE_URL = process.env.PUBLIC_URL ?? "https://sexy.pivoine.art";
+
+export interface RenderOptions {
+  url: string;
+  [key: string]: unknown;
+}
+
+export async function renderTemplate(
+  name: string,
+  locals: RenderOptions,
+): Promise<string> {
+  // Dynamic import: @maizzle/framework v6 is ESM-only
+  const { render } = await import("@maizzle/framework");
+
+  const html = await readFile(path.join(TEMPLATES_ROOT, `${name}.html`), "utf8");
+
+  const { html: rendered } = await render(html, {
+    components: {
+      root: TEMPLATES_ROOT,
+      folders: ["layouts"],
+    },
+    // Override PostCSS `from` so @tailwindcss/postcss resolves @import "@maizzle/tailwindcss"
+    // from this package's node_modules (defu gives our value priority over the cwd default).
+    postcss: {
+      options: {
+        from: path.join(PKG_ROOT, "email.css"),
+      },
+    },
+    locals: {
+      baseUrl: BASE_URL,
+      ...locals,
+    },
+  });
+
+  return rendered;
+}