feat: extract shop from mp/shop — initial libreshop/shop

Source moved verbatim from mp/shop/ on 2026-04-29; mp was the first
concrete adapter consuming the libreshop toolkit. Builds and publishes
git.librete.ch/libreshop/shop on every main / v* push via the standard
.gitea/workflows/build.yml shared across libreshop components.

server/api/contact.post.ts

@@ -0,0 +1,55 @@
+export default defineEventHandler(async (event) => {
+	const body = await readBody(event);
+
+	const { name, email, subject, message } = body;
+
+	if (!name || !email || !message) {
+		throw createError({
+			statusCode: 400,
+			message: "Name, E-Mail und Nachricht sind erforderlich",
+		});
+	}
+
+	// Validate email format
+	const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
+	if (!emailRegex.test(email)) {
+		throw createError({
+			statusCode: 400,
+			message: "Ungültige E-Mail-Adresse",
+		});
+	}
+
+	try {
+		// Send email via Mail service
+		const config = useRuntimeConfig();
+		const mailApiUrl = config.mailApiUrl || "http://mail:2222";
+
+		await $fetch(`${mailApiUrl}/send`, {
+			method: "POST",
+			body: {
+				to: "paperwork@muellerprints.de",
+				subject: `Kontaktanfrage: ${subject || "Anfrage über Website"}`,
+				body: `
+Name: ${name}
+E-Mail: ${email}
+Betreff: ${subject || "Kontaktanfrage über Website"}
+
+Nachricht:
+${message}
+
+---
+Diese Nachricht wurde über das Kontaktformular auf muellerprints.de gesendet.
+				`.trim(),
+				replyTo: email,
+			},
+		});
+
+		return { success: true };
+	} catch (error) {
+		console.error("Failed to send contact email:", error);
+		throw createError({
+			statusCode: 500,
+			message: "E-Mail konnte nicht gesendet werden",
+		});
+	}
+});