feat: notifications inbox page

The bell only ever showed the last 30; add a full paginated /notifications
page, per-notification mark-read, and a shared notificationHref helper so
the bell and the page route identically instead of duplicating the logic.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/web/app/(app)/notifications/page.tsx

@@ -0,0 +1,13 @@
+import type { Metadata } from "next";
+import { headers } from "next/headers";
+import { auth } from "@/lib/auth/server";
+import { NotificationsPageContent } from "@/components/notifications/notifications-page-content";
+
+export const metadata: Metadata = {};
+
+export default async function NotificationsPage() {
+  const session = await auth.api.getSession({ headers: await headers() });
+  if (!session) return null;
+
+  return <NotificationsPageContent />;
+}