feat(v0.1.7): port iperf3 configurable + iperf3 docker sur port 5202

- config.toml: nouveau champ [server] iperf3_port (défaut 5201)
- network_info: iperf3 -p <port> utilise le port configuré
- docker-compose: iperf3 exposé sur 5202 (5201 occupé par linux_benchtools)

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

server/docker-compose.yml

@@ -29,5 +29,17 @@ services:
     depends_on:
       - server
 
+  iperf3:
+    build:
+      context: .
+      dockerfile: Dockerfile.iperf3
+      args:
+        ALPINE_IMAGE: ${ALPINE_IMAGE:-public.ecr.aws/docker/library/alpine:latest}
+    restart: unless-stopped
+    command: ["-s"]
+    ports:
+      - "5202:5201/tcp"
+      - "5202:5201/udp"
+
 volumes:
   nanometrics_data: