feat: OISEnhancedBlock — rate curve, implied pts, scénarios charts per CB

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

app/api/yields/route.ts

@@ -1,13 +1,43 @@
 import { NextResponse } from "next/server";
 import { fetchTEBondYields } from "@/lib/tebonds";
 
+// Variation % d'un pair FX vs clôture J-1 (Yahoo Finance, cache 5 min)
+// Valeur positive = devise X plus forte vs USD (ou USD plus fort si pair inversé)
+async function fxChangePct(symbol: string, invert = false): Promise<number | null> {
+  try {
+    const res = await fetch(
+      `https://query1.finance.yahoo.com/v8/finance/chart/${encodeURIComponent(symbol)}?interval=1d&range=2d`,
+      { next: { revalidate: 300 }, headers: { "User-Agent": "Mozilla/5.0" } }
+    );
+    if (!res.ok) return null;
+    const meta = (await res.json())?.chart?.result?.[0]?.meta as { regularMarketPrice?: number; chartPreviousClose?: number } | undefined;
+    const cur  = meta?.regularMarketPrice ?? null;
+    const prev = meta?.chartPreviousClose ?? null;
+    if (cur === null || prev === null || prev === 0) return null;
+    const pct = (cur - prev) / prev * 100;
+    return parseFloat((invert ? -pct : pct).toFixed(3));
+  } catch { return null; }
+}
+
 // 10Y sovereign yields — source unique : tradingeconomics.com/bonds (HTML statique)
 // Remplace les sources précédentes (FRED DGS10 + IRLTLT01XXM156N mensuel + ECB/BoE APIs)
 // qui avaient des décalages allant de 1 jour (FRED daily) à 1 mois (FRED monthly JPY/CHF/AUD/NZD).
 // TE bonds = données du jour pour les 8 devises, cache 1h.
 
 export async function GET() {
-  const bondData = await fetchTEBondYields();
+  const [bondData, fxResults] = await Promise.all([
+    fetchTEBondYields(),
+    Promise.all([
+      fxChangePct("EURUSD=X"),          // EUR: positif = EUR fort
+      fxChangePct("GBPUSD=X"),          // GBP: positif = GBP fort
+      fxChangePct("USDJPY=X", true),    // JPY: inversé (USD/JPY haut = JPY faible)
+      fxChangePct("USDCHF=X", true),    // CHF: inversé
+      fxChangePct("USDCAD=X", true),    // CAD: inversé
+      fxChangePct("AUDUSD=X"),          // AUD: positif = AUD fort
+      fxChangePct("NZDUSD=X"),          // NZD: positif = NZD fort
+    ]),
+  ]);
+  const [eurFx, gbpFx, jpyFx, chfFx, cadFx, audFx, nzdFx] = fxResults;
 
   const yields: Record<string, number | null> = {
     USD: bondData.USD?.yield10y ?? null,
@@ -42,5 +72,17 @@ export async function GET() {
     }
   }
 
-  return NextResponse.json({ yields, spreads, dayDeltas, timestamp: Date.now() });
+  // Variation FX journalière par devise (positif = devise forte vs USD)
+  const fxDayPct: Record<string, number | null> = {
+    USD: 0,
+    EUR: eurFx,
+    GBP: gbpFx,
+    JPY: jpyFx,
+    CHF: chfFx,
+    CAD: cadFx,
+    AUD: audFx,
+    NZD: nzdFx,
+  };
+
+  return NextResponse.json({ yields, spreads, dayDeltas, fxDayPct, timestamp: Date.now() });
 }