fix: limite dynamique pour fetchTransfers selon la période

Hardcoder limit=2000 ne couvrait que ~5 jours (400 tx/jour × 5 = 2000).
La limite est maintenant calculée : max(2000, periodDays × 600).
- 1j  → 2000  (inchangé)
- 7j  → 4200
- 30j → 18000  (couvre ~45 jours de marge)

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

src/services/DataService.ts

@@ -37,7 +37,9 @@ async function fetchLiveTransactions(periodDays: number): Promise<{
   totalCount: number;
   totalVolume: number;
 }> {
-  const { transfers: rawTransfers, totalCount } = await fetchTransfers(periodDays);
+  // ~400 tx/jour sur le réseau Ğ1v2 → marge ×1.5 arrondie, minimum 2000
+  const limit = Math.max(2000, Math.ceil(periodDays * 600));
+  const { transfers: rawTransfers, totalCount } = await fetchTransfers(periodDays, limit);
   if (rawTransfers.length === 0) return { geolocated: [], totalCount: 0, totalVolume: 0 };
 
   const totalVolume = rawTransfers.reduce((s, t) => s + t.amount, 0);