feat(agent-scan-network): implémentation Phase 2 — découverte réseau

- Scan ping TCP multi-ports (sans root requis)
- Lecture table ARP Linux (/proc/net/arp)
- Détection 20 services par scan de ports TCP
- Base OUI embarquée (~70 constructeurs courants)
- API JSON locale Axum sur :9100 (GET /devices, GET /health)
- Push automatique vers backend /api/v1/network
- Enregistrement agent au démarrage
- Config YAML (subnet 10.0.0.0/22, concurrence, timeouts)
- ROADMAP Phase 1 et 2 marquées complètes

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

agents/agent-scan-network/Cargo.toml

@@ -4,10 +4,15 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
-tokio       = { workspace = true }
-serde       = { workspace = true }
-serde_json  = { workspace = true }
-anyhow      = { workspace = true }
-tracing     = { workspace = true }
+tokio            = { workspace = true }
+serde            = { workspace = true }
+serde_json       = { workspace = true }
+anyhow           = { workspace = true }
+tracing          = { workspace = true }
 tracing-subscriber = { workspace = true }
-axum        = "0.8"
+axum             = "0.8"
+serde_yaml       = "0.9"
+reqwest          = { version = "0.12", features = ["json"] }
+chrono           = { version = "0.4", features = ["serde"] }
+ipnetwork        = "0.20"
+tokio-util       = "0.7"