fix: Backfill-Stall-Guard gegen Endlosschleife am History-Ende

src/server/scripts/backfill.ts

@@ -10,6 +10,7 @@ const since = Date.now() - TARGET_MONTHS * 30 * 24 * 60 * 60 * 1000;
 for (const pair of PAIRS) {
   let endTs: number | undefined = undefined;
   let total = 0;
+  let prevOldest: number | undefined = undefined;
   for (;;) {
     const batch = await fetchCandles(pair, '15m', 300, endTs);
     if (batch.length === 0) break;
@@ -23,7 +24,10 @@ for (const pair of PAIRS) {
     await insertCandles(pair, closed);
     total += closed.length;
 
+    // Cursor aus batch (nicht closed): auch die laufende Candle schiebt die Paginierung zurück
     const oldest = Math.min(...batch.map((c) => c.ts));
+    if (prevOldest !== undefined && oldest >= prevOldest) break; // API-History-Ende erreicht
+    prevOldest = oldest;
     if (oldest <= since) break;
     endTs = oldest - 1;
     await Bun.sleep(200); // Rate-Limit-Schonung