feat: retail sales MoM (TE scraping), smart cache, IL weekly delta arrows, OIS phase labels

- Retail Sales: switch from FRED OECD series (4-6w lag) to Trading Economics real-time scraping
  for all 8 currencies; label changed to "Retail Sales MoM"
- Cache TTL: 24h → 1h base + 15min hot when ForexFactory detects recent high-impact event
- Rate probability trend arrows: server-side IL weekly delta (current vs previous Dellamotta article)
  with per-metric thresholds (prob ≥3%/10%, bps ≥10/25) and colour coding (sky=dovish, amber=hawkish)
- Cycle phase: replaced FRED trend heuristic with OIS-based logic using peakMeeting.probMovePct,
  probIsCut, and yearEndBps; dynamic descriptions include real market numbers
- investinglive.ts: find both current + previous article to compute week-over-week delta server-side

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

lib/investinglive.ts

@@ -36,28 +36,89 @@ export interface ILRateExpectation {
 
 export type ILExpectationsMap = Partial<Record<Currency, ILRateExpectation>>;
 
-// ── URL discovery ─────────────────────────────────────────────────────────────
-// Try the last 14 days to find the most recently published article.
+export interface ILExpectationsWithHistory {
+  current:  ILExpectationsMap;
+  prev:     ILExpectationsMap;
+  prevDate: string | null;
+}
 
-async function findLatestArticleUrl(): Promise<{ url: string; dateStr: string } | null> {
-  for (let daysAgo = 0; daysAgo <= 14; daysAgo++) {
-    const d = new Date(Date.now() - daysAgo * 86400000);
-    const yyyymmdd = d.toISOString().slice(0, 10).replace(/-/g, "");
-    const url = `https://investinglive.com/news/how-have-interest-rate-expectations-changed-after-this-weeks-event-${yyyymmdd}/`;
-    try {
-      const res = await fetch(url, {
-        method:  "HEAD",
-        headers: { "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 Chrome/124.0.0.0 Safari/537.36" },
-        next:    { revalidate: 21600 }, // re-check every 6h
-      });
-      if (res.ok) return { url, dateStr: `${yyyymmdd.slice(0,4)}-${yyyymmdd.slice(4,6)}-${yyyymmdd.slice(6,8)}` };
-    } catch { /* try next day */ }
+// ── URL discovery ─────────────────────────────────────────────────────────────
+
+interface ArticleRef { url: string; dateStr: string; daysAgo: number; }
+
+async function tryUrl(daysAgo: number): Promise<ArticleRef | null> {
+  const d = new Date(Date.now() - daysAgo * 86_400_000);
+  const yyyymmdd = d.toISOString().slice(0, 10).replace(/-/g, "");
+  const dateStr  = `${yyyymmdd.slice(0,4)}-${yyyymmdd.slice(4,6)}-${yyyymmdd.slice(6,8)}`;
+  const url = `https://investinglive.com/news/how-have-interest-rate-expectations-changed-after-this-weeks-event-${yyyymmdd}/`;
+  try {
+    const res = await fetch(url, {
+      method:  "HEAD",
+      headers: { "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 Chrome/124.0.0.0 Safari/537.36" },
+      next:    { revalidate: 21600 },
+    });
+    return res.ok ? { url, dateStr, daysAgo } : null;
+  } catch { return null; }
+}
+
+// Find current article (last 14 days) + previous article (14 days before current, up to 21 days)
+async function findArticleRefs(): Promise<{ current: ArticleRef | null; previous: ArticleRef | null }> {
+  let current: ArticleRef | null = null;
+
+  for (let d = 0; d <= 14; d++) {
+    const found = await tryUrl(d);
+    if (found) { current = found; break; }
+  }
+
+  if (!current) return { current: null, previous: null };
+
+  let previous: ArticleRef | null = null;
+  // Start the day after the current article and look up to 21 days further back
+  for (let d = current.daysAgo + 1; d <= current.daysAgo + 21; d++) {
+    const found = await tryUrl(d);
+    if (found) { previous = found; break; }
+  }
+
+  return { current, previous };
+}
+
+// ── Article fetch + parse ─────────────────────────────────────────────────────
+
+async function fetchAndParse(ref: ArticleRef): Promise<ILExpectationsMap> {
+  try {
+    const res = await fetch(ref.url, {
+      headers: {
+        "User-Agent":      "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 Chrome/124.0.0.0 Safari/537.36",
+        "Accept":          "text/html,application/xhtml+xml",
+        "Accept-Language": "en-US,en;q=0.9",
+      },
+      next: { revalidate: 21600 },
+    });
+    if (!res.ok) return {};
+
+    const html = await res.text();
+    const jsonLdMatch = html.match(/"articleBody"\s*:\s*"((?:[^"\\]|\\.)*)"/);
+    if (!jsonLdMatch) {
+      console.warn("[IL] articleBody not found:", ref.url);
+      return {};
+    }
+
+    const body = jsonLdMatch[1]
+      .replace(/\\n/g, "\n")
+      .replace(/\\"/g, '"')
+      .replace(/\\u003c/g, "<")
+      .replace(/\\u003e/g, ">");
+
+    const result = parseArticleBody(body, ref.dateStr);
+    console.log(`[IL] Parsed ${Object.keys(result).length} CBs from article dated ${ref.dateStr}`);
+    return result;
+  } catch (err) {
+    console.error("[IL] fetch error:", err);
+    return {};
   }
-  return null;
 }
 
 // ── Article parser ─────────────────────────────────────────────────────────────
-// The structured data JSON-LD "articleBody" contains the raw text we need.
 
 function parseArticleBody(text: string, publishedDate: string): ILExpectationsMap {
   const result: ILExpectationsMap = {};
@@ -65,10 +126,6 @@ function parseArticleBody(text: string, publishedDate: string): ILExpectationsMa
   // Matches: "RBNZ: 75 bps (79% probability of rate hike at the next meeting)"
   //          "Fed: 13 bps (99% probability of no change at the next meeting)"
   //          "ECB: 53 bps (99% probability of rate cut at the next meeting)"
-  // Note: bps value in the article is always unsigned — sign is inferred from direction.
-  //   rate hike  → positive bps (rate going up)
-  //   rate cut   → negative bps (rate going down)
-  //   no change  → keep unsigned (residual expectation for later meetings)
   const linePattern = /([A-Za-z]+)\s*:\s*(-?\d+)\s*bps\s*\(\s*(\d+)%\s*probability\s+of\s+(rate\s+(?:hike|cut)|no\s+change)\s+at\s+the\s+next\s+meeting\)/gi;
 
   let m: RegExpExecArray | null;
@@ -83,15 +140,13 @@ function parseArticleBody(text: string, publishedDate: string): ILExpectationsMa
     const nextMeetingIsHike     = !nextMeetingIsNoChange && direction.includes("hike");
     const nextMeetingIsCut      = !nextMeetingIsNoChange && direction.includes("cut");
 
-    // Apply sign: if direction is cut and value is positive, negate it
     let bpsYearEnd = parseInt(bpsStr);
     if (nextMeetingIsCut && bpsYearEnd > 0) bpsYearEnd = -bpsYearEnd;
 
-    // Probability of change = 100 - probNoChange  OR  directProb if it's a hike/cut
     const nextMeetingProbPct = nextMeetingIsNoChange ? 100 - probPct : probPct;
 
     result[ccy] = {
-      currency:              ccy,
+      currency: ccy,
       nextMeetingProbPct,
       nextMeetingIsHike,
       nextMeetingIsNoChange,
@@ -103,50 +158,31 @@ function parseArticleBody(text: string, publishedDate: string): ILExpectationsMa
   return result;
 }
 
-// ── Main fetch ────────────────────────────────────────────────────────────────
+// ── Exports ───────────────────────────────────────────────────────────────────
 
+/** Retourne uniquement l'article le plus récent (compatibilité descendante). */
 export async function fetchILExpectations(): Promise<ILExpectationsMap> {
-  try {
-    const found = await findLatestArticleUrl();
-    if (!found) {
-      console.warn("[IL] No recent rate-expectations article found (last 14 days)");
-      return {};
-    }
-
-    const res = await fetch(found.url, {
-      headers: {
-        "User-Agent":      "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 Chrome/124.0.0.0 Safari/537.36",
-        "Accept":          "text/html,application/xhtml+xml",
-        "Accept-Language": "en-US,en;q=0.9",
-      },
-      next: { revalidate: 21600 }, // cache 6h — new article only published after major events
-    });
-    if (!res.ok) {
-      console.warn("[IL] Fetch failed:", res.status);
-      return {};
-    }
-
-    const html = await res.text();
-
-    // Extract articleBody from JSON-LD structured data
-    const jsonLdMatch = html.match(/"articleBody"\s*:\s*"((?:[^"\\]|\\.)*)"/);
-    if (!jsonLdMatch) {
-      console.warn("[IL] articleBody not found in JSON-LD");
-      return {};
-    }
-
-    const articleBody = jsonLdMatch[1]
-      .replace(/\\n/g, "\n")
-      .replace(/\\"/g, '"')
-      .replace(/\\u003c/g, "<")
-      .replace(/\\u003e/g, ">");
-
-    const parsed = parseArticleBody(articleBody, found.dateStr);
-    const count = Object.keys(parsed).length;
-    console.log(`[IL] Parsed ${count} CBs from article dated ${found.dateStr}`);
-    return parsed;
-  } catch (err) {
-    console.error("[IL] error:", err);
+  const { current } = await findArticleRefs();
+  if (!current) {
+    console.warn("[IL] No recent rate-expectations article found (last 14 days)");
     return {};
   }
+  return fetchAndParse(current);
+}
+
+/** Retourne l'article courant ET l'article précédent pour calcul de delta semaine/semaine. */
+export async function fetchILExpectationsWithHistory(): Promise<ILExpectationsWithHistory> {
+  const { current, previous } = await findArticleRefs();
+
+  if (!current) {
+    console.warn("[IL] No recent rate-expectations article found (last 14 days)");
+    return { current: {}, prev: {}, prevDate: null };
+  }
+
+  const [currentData, prevData] = await Promise.all([
+    fetchAndParse(current),
+    previous ? fetchAndParse(previous) : Promise.resolve({} as ILExpectationsMap),
+  ]);
+
+  return { current: currentData, prev: prevData, prevDate: previous?.dateStr ?? null };
 }