feat: WTI/Brent via Stooq, PMI scraping (TE), Groq replace Bytez

- drivers: switch Brent (cb.f) and WTI (cl.f) from stale FRED to Stooq
  near-real-time futures — same stooqMetal() already used for gold/silver
- macro: add scrapePMI() to scrape Trading Economics meta description for
  manufacturing-pmi and services-pmi for all 8 currencies (no API key needed)
- narrative: replace dead Bytez API with Groq (OpenAI-compatible, free tier)
  env var renamed BYTEZ_API_KEY → GROQ_API_KEY, model llama-3.1-8b-instant
- NarrativeButton: rebrand "Erreur Bytez" / "Bytez AI" → "Erreur IA" / "Groq AI"

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/api/drivers/route.ts

@@ -105,12 +105,16 @@ export async function GET() {
 
   // 1. Marchés indices — FRED (données fin de journée, cache 24h)
   //    VIXCLS = VIX clôture CBOE | SP500 = S&P 500
-  //    DCOILBRENTEU = Brent | DCOILWTICO = WTI
-  const [vixQ, sp500Q, brentQ, wtiQ] = await Promise.all([
-    fredObsDelta("VIXCLS",       fredKey),
-    fredObsDelta("SP500",        fredKey),
-    fredObsDelta("DCOILBRENTEU", fredKey),
-    fredObsDelta("DCOILWTICO",   fredKey),
+  const [vixQ, sp500Q] = await Promise.all([
+    fredObsDelta("VIXCLS", fredKey),
+    fredObsDelta("SP500",  fredKey),
+  ]);
+
+  // Pétrole — Stooq futures (quasi temps réel, cache 5 min, sans clé API)
+  //   cl.f = WTI NYMEX | cb.f = Brent ICE  → delta = variation intraday vs ouverture
+  const [brentQ, wtiQ] = await Promise.all([
+    stooqMetal("cb.f"),
+    stooqMetal("cl.f"),
   ]);
 
   // 2. Métaux précieux — Stooq (quasi temps réel, cache 5 min, sans clé API)