feat: resolve live Nostr references in blog posts and add embeds

Support naddr/nevent/note slugs for unindexed posts, cache naddr lookups,
render Nostr embeds in markdown, and add a consistency check for events mirrors.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/lib/meetupsData.ts

@@ -0,0 +1,71 @@
+/**
+ * Single source of truth for meetup data used by the public /events page, the
+ * /events.md mirror, and the /llms.txt summary line. Centralizing the fetch +
+ * upcoming/past partition guarantees those three can never disagree on the count.
+ *
+ * Fetched with `no-store` so every render reflects the live backend — this is
+ * what keeps crawlers (which don't run JS) and llms.txt consumers from seeing a
+ * stale or build-time-empty list.
+ */
+import { apiUrl } from "./api-base";
+import { getMeetupStartUtc } from "./meetupEventTime";
+
+export interface Meetup {
+  id: string;
+  title: string;
+  date: string;
+  time?: string;
+  location?: string;
+  description?: string;
+  status?: string;
+  organizer?: { name?: string; slug?: string } | null;
+  [key: string]: unknown;
+}
+
+/** Fetch all publicly-visible meetups from the backend, live (uncached). */
+export async function fetchMeetupsLive(): Promise<Meetup[]> {
+  try {
+    const res = await fetch(apiUrl("/meetups"), { cache: "no-store" });
+    if (!res.ok) return [];
+    const data = await res.json();
+    return Array.isArray(data) ? (data as Meetup[]) : [];
+  } catch {
+    return [];
+  }
+}
+
+export interface PartitionedMeetups {
+  upcoming: Meetup[];
+  past: Meetup[];
+}
+
+/**
+ * Split meetups into upcoming (start >= now, soonest first) and past (start <
+ * now, most recent first). Meetups with an unparseable date are dropped.
+ */
+export function partitionMeetups(
+  meetups: Meetup[],
+  now: Date = new Date(),
+): PartitionedMeetups {
+  const upcoming: Meetup[] = [];
+  const past: Meetup[] = [];
+
+  for (const m of meetups) {
+    const start = getMeetupStartUtc(m.date, m.time || "00:00");
+    if (Number.isNaN(start.getTime())) continue;
+    if (start >= now) upcoming.push(m);
+    else past.push(m);
+  }
+
+  const startMs = (m: Meetup) =>
+    getMeetupStartUtc(m.date, m.time || "00:00").getTime();
+  upcoming.sort((a, b) => startMs(a) - startMs(b));
+  past.sort((a, b) => startMs(b) - startMs(a));
+
+  return { upcoming, past };
+}
+
+/** Number of upcoming meetups — the single value llms.txt and events.md share. */
+export function countUpcoming(meetups: Meetup[], now: Date = new Date()): number {
+  return partitionMeetups(meetups, now).upcoming.length;
+}