Optimize AS detail queries and increase PrefixHandler batch size

- Increase PrefixHandler batch size from 20k to 25k (25% increase)
- Add missing index on origin_asn for live_routes table
- This index significantly speeds up AS detail page queries
- Add code to create missing indexes on existing databases

internal/database/database.go

@@ -127,6 +127,16 @@ func (d *Database) Initialize() error {
 		d.logger.Warn("Failed to VACUUM database", "error", err)
 	}
 
+	// Create any missing indexes for existing databases
+	missingIndexes := []string{
+		"CREATE INDEX IF NOT EXISTS idx_live_routes_origin_asn ON live_routes(origin_asn)",
+	}
+	for _, idx := range missingIndexes {
+		if err := d.exec(idx); err != nil {
+			d.logger.Warn("Failed to create index", "index", idx, "error", err)
+		}
+	}
+
 	return nil
 }