Add green-bean inventory and cupping features

Ports inventory management and SCA-style cupping scoring from
hope_roaster: lot tracking with audit-logged consumption, cupping
sessions with server-authoritative scoring and a live radar chart,
and links from the planner (draw-from-lot, open-cupping-session).

Also fixes the Blend/Single-origin toggle layout, replaces tooltips
with an in-context "why" teaching layer, and stages the planner UI
into pre-roast vs. post-roast phases.

server/db.js

@@ -13,7 +13,11 @@ export function createDb(connectionString = process.env.DATABASE_URL) {
 				? { rejectUnauthorized: true }
 				: undefined,
 	});
-	return { query: (...args) => pool.query(...args), close: () => pool.end() };
+	return {
+		query: (...args) => pool.query(...args),
+		connect: () => pool.connect(),
+		close: () => pool.end(),
+	};
 }
 
 /** Apply each versioned SQL file once; failed migrations are not recorded. */

server/mailer.js

@@ -0,0 +1,9 @@
+/** Sends transactional email via SMTP when configured; the caller decides what to do when this
+ * returns false (e.g. log the link so an admin can hand it to the user manually). */
+export async function sendMail({ smtpUrl, from, to, subject, text }) {
+	if (!smtpUrl) return false;
+	const { default: nodemailer } = await import("nodemailer");
+	const transporter = nodemailer.createTransport(smtpUrl);
+	await transporter.sendMail({ from, to, subject, text });
+	return true;
+}