feat: packet capture, bandwidth test (v0.11.5 Beta)

- Packet capture: RouterOS sniffer + SFTP download to PCAP for Wireshark analysis
- Bandwidth test: RouterOS /tool/bandwidth-test with TX/RX Mbps result display
- Both exposed in the Tools tab on device detail pages

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

backend/src/services/mikrotik/DeviceCollector.ts

@@ -32,6 +32,7 @@ export interface DeviceRow {
   name: string;
   ip_address: string;
   api_port: number;
+  ssh_port?: number;
   api_username: string;
   api_password_encrypted: string;
   ssh_username?: string;