feat: shop buy, forum replies, tickets, messages, sessions, and UX hardening

Complete remaining product gaps: credit-based shop purchases, guild thread replies, help ticket detail/reply/close, offline message compose, sign-out-everywhere via JWT version, ads delete confirm, soft-fail feedback, rate limits, loading states, and single auth() in site layout.

Co-authored-by: Cursor <[email protected]>

src/components/site-header.tsx

@@ -1,15 +1,13 @@
 import Image from "next/image";
 import Link from "next/link";
 import { getTranslations } from "next-intl/server";
-import { auth } from "@/lib/auth";
 import { cached } from "@/lib/cache";
 import { prisma } from "@/lib/prisma";
 import { siteSettings } from "@/lib/services/site-settings";
 
 export async function SiteHeader() {
 	const t = await getTranslations("header");
-	const [_session, hotelName, header, logo] = await Promise.all([
-		auth(),
+	const [hotelName, header, logo] = await Promise.all([
 		siteSettings.get("hotel_name", "Atom"),
 		siteSettings.get("cms_header", "/assets/images/background.png"),
 		siteSettings.get("cms_logo", ""),