Fix multi-month scrape coverage and add duo MUSIC EXCHANGE

- Extend 8 scrapers (liquid-room, shibuya-o, club-quattro, meets-otsuka,
  nishieifuku-jam, fever-shindaita, fad-yokohama, and new duo-music-exchange)
  to fetch 3 calendar months instead of 1-2, covering the full 65-day window
- Add duo MUSIC EXCHANGE scraper (渋谷, ~700 cap, /schedule/YYYY/index_YYYY-MM.html)
- Add npm test: Node.js built-in test runner verifies each scraper fetches
  all required month URLs via mocked fetch (10 tests, no extra deps)

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

1 files changed, 11 insertions, 20 deletions

diff --git a/app/scrapers/fad-yokohama.ts b/app/scrapers/fad-yokohama.ts
index a01ea0d..f8f7cbc 100644
--- a/app/scrapers/fad-yokohama.ts
+++ b/app/scrapers/fad-yokohama.ts
@@ -151,27 +151,18 @@ function parsePageEvents(
 export const scraper: Scraper = {
   venue,
   async scrape(): Promise<EventInput[]> {
-    const res = await fetch(SCHEDULE_URL);
-    if (!res.ok) throw new Error(`HTTP ${res.status}`);
-    const html = await res.text();
-
-    const { year, month, nextUrl } = getMonthContext(html);
-    const events = parsePageEvents(html, year, month, SCHEDULE_URL);
-
-    if (nextUrl) {
-      const nextRes = await fetch(nextUrl);
-      if (nextRes.ok) {
-        const nextHtml = await nextRes.text();
-        let nextMonth = month + 1;
-        let nextYear = year;
-        if (nextMonth > 12) {
-          nextMonth = 1;
-          nextYear++;
-        }
-        events.push(...parsePageEvents(nextHtml, nextYear, nextMonth, nextUrl));
-      }
+    const allEvents: EventInput[] = [];
+    let url: string | null = SCHEDULE_URL;
+
+    for (let page = 0; page < 3 && url; page++) {
+      const res = await fetch(url);
+      if (!res.ok) break;
+      const html = await res.text();
+      const { year, month, nextUrl } = getMonthContext(html);
+      allEvents.push(...parsePageEvents(html, year, month, url));
+      url = nextUrl;
     }
 
-    return events;
+    return allEvents;
   },
 };