feat(macro-vibes): rename BTC Signal → Macro Vibes; add MacroPanel UI

Module rename across page H1, navbar tab, URL (/en/btc → /en/macro),
all metadata/JSON-LD, sitemap, llms.txt, opengraph image, and SystemControl
copy. Old /btc route fully removed.

New components/btc/MacroPanel.tsx polls /api/macro/snapshot and lays out
the 8 indicators in four sections (Valuation / Bottom trigger reference /
Market structure / Sentiment & flows / Positioning) with tone-coloured
values, current-band threshold chips, and a single CoinGlass / source
chart link per card. Composite -100..+100 needle pulses on score change.

Also fixes the pinned bottom-reversal alert on the homepage, which still
linked to the now-404 /en/btc — now routes to /en/macro.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

app/[locale]/posts/page.tsx

@@ -4,11 +4,15 @@ import { redirect } from 'next/navigation'
  * Legacy route. The old "Signals" hub was replaced by two top-level nav
  * tabs (Trump / BTC). Anything still pointing here (old links, sitemap,
  * bookmarks) lands on the Trump system page.
+ *
+ * NOTE: Next.js 15+ made `params` async. Without `await` we'd interpolate
+ * the still-pending Promise as `undefined` and ship users to /undefined/trump.
  */
-export default function LegacySignalsRedirect({
+export default async function LegacySignalsRedirect({
   params,
 }: {
-  params: { locale: string }
+  params: Promise<{ locale: string }>
 }) {
-  redirect(`/${params.locale}/trump`)
+  const { locale } = await params
+  redirect(`/${locale}/trump`)
 }