feat(web): public mesh stats counter + /api/public/stats endpoint

Live social-proof counter on the landing page, tied to the E2E
narrative. Formatted as understated mono footer, not hero brag.

Backend — new GET /api/public/stats (unauthed, 60s in-memory cache):
  {
    messagesRouted: SELECT COUNT(*) FROM mesh.message_queue,
    meshesCreated: SELECT COUNT(*) FROM mesh.mesh WHERE archivedAt IS NULL,
    peersActive: SELECT COUNT(*) FROM mesh.presence WHERE disconnectedAt IS NULL,
    lastUpdated: ISO timestamp,
  }

Aggregate counts only — no ids, no names, no ciphertext, no routing
metadata. Safe for public consumption. cache-control header sets
public/s-maxage=60 for edge caching. `x-cache: HIT|MISS` for debug.

Frontend — new MeshStats Server Component at
modules/marketing/home/mesh-stats.tsx. Reads the endpoint server-side
via the ~/lib/api/server client, renders monospace footer:

  ciphertext routed → 4,217 messages · 12 meshes · 8 peers online
  broker sees none of it

Graceful zero state: when messagesRouted === 0 shows
"ciphertext → ready to route" instead of embarrassing zeros. Tabular-
nums for the numeric spans so they don't jitter across renders.

Mounted between <CallToAction /> and <LatestNewsToaster />. Page-level
`export const revalidate = 60` so Next.js ISR refreshes the counter
every minute without a DB hit on every request (combined with the
API cache = two-layer 60s TTL, DB sees ~1 query/minute).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/web/src/app/[locale]/(marketing)/page.tsx

@@ -9,8 +9,14 @@ import { DemoDashboard } from "~/modules/marketing/home/demo-dashboard";
 import { WhatIsClaudemesh } from "~/modules/marketing/home/what-is-claudemesh";
 import { FAQ } from "~/modules/marketing/home/faq";
 import { CallToAction } from "~/modules/marketing/home/cta";
+import { MeshStats } from "~/modules/marketing/home/mesh-stats";
 import { LatestNewsToaster } from "~/modules/marketing/home/toaster";
 
+// Revalidate the page every 60s so the mesh-stats counter stays fresh
+// without hammering the DB. The /api/public/stats endpoint has its own
+// 60s in-memory cache too.
+export const revalidate = 60;
+
 const HomePage = () => {
   return (
     <div
@@ -28,6 +34,7 @@ const HomePage = () => {
       <BeyondTerminal />
       <FAQ />
       <CallToAction />
+      <MeshStats />
       <LatestNewsToaster />
     </div>
   );