Optimize database batch operations with prepared statements

- Add prepared statements to all batch operations for better performance
- Fix database lock contention by properly batching operations
- Update SQLite settings for extreme performance (8GB cache, sync OFF)
- Add proper error handling for statement closing
- Update tests to properly track batch operations

internal/routewatch/peerhandler.go

@@ -135,18 +135,22 @@ func (h *PeerHandler) flushBatchLocked() {
 		}
 	}
 
-	// Apply updates
-	for _, update := range peerMap {
-		if err := h.db.UpdatePeer(update.peerIP, update.peerASN, update.messageType, update.timestamp); err != nil {
-			h.logger.Error("Failed to update peer",
-				"peer", update.peerIP,
-				"peer_asn", update.peerASN,
-				"message_type", update.messageType,
-				"error", err,
-			)
+	// Convert to database format
+	dbPeerMap := make(map[string]database.PeerUpdate)
+	for peerIP, update := range peerMap {
+		dbPeerMap[peerIP] = database.PeerUpdate{
+			PeerIP:      update.peerIP,
+			PeerASN:     update.peerASN,
+			MessageType: update.messageType,
+			Timestamp:   update.timestamp,
 		}
 	}
 
+	// Process all peers in a single batch transaction
+	if err := h.db.UpdatePeerBatch(dbPeerMap); err != nil {
+		h.logger.Error("Failed to process peer batch", "error", err, "count", len(dbPeerMap))
+	}
+
 	// Clear batch
 	h.peerBatch = h.peerBatch[:0]
 	h.lastFlush = time.Now()