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/src/config.rs

@@ -0,0 +1,61 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Clone, Deserialize, Serialize)]
+pub struct Config {
+    pub backend: BackendConfig,
+    pub agent:   AgentConfig,
+    pub scan:    ScanConfig,
+    pub api:     ApiConfig,
+}
+
+#[derive(Debug, Clone, Deserialize, Serialize)]
+pub struct BackendConfig {
+    pub url:   String,
+    pub token: String,
+}
+
+#[derive(Debug, Clone, Deserialize, Serialize)]
+pub struct AgentConfig {
+    pub id:       String,
+    pub hostname: String,
+}
+
+#[derive(Debug, Clone, Deserialize, Serialize)]
+pub struct ScanConfig {
+    pub subnets:             Vec<String>,
+    pub interval_seconds:    u64,
+    pub ping_timeout_ms:     u64,
+    pub service_timeout_ms:  u64,
+    pub concurrency:         usize,
+    pub ports:               Vec<u16>,
+}
+
+#[derive(Debug, Clone, Deserialize, Serialize)]
+pub struct ApiConfig {
+    pub listen: String,
+}
+
+impl Config {
+    pub fn load(path: &str) -> anyhow::Result<Self> {
+        let content = std::fs::read_to_string(path)?;
+        let mut cfg: Config = serde_yaml::from_str(&content)?;
+        cfg.resolve_defaults();
+        Ok(cfg)
+    }
+
+    fn resolve_defaults(&mut self) {
+        if self.agent.hostname.is_empty() {
+            self.agent.hostname = detect_hostname();
+        }
+        if self.agent.id.is_empty() {
+            self.agent.id = format!("scan-{}", self.agent.hostname);
+        }
+    }
+}
+
+fn detect_hostname() -> String {
+    // Lecture directe de /etc/hostname (Linux)
+    std::fs::read_to_string("/etc/hostname")
+        .map(|s| s.trim().to_string())
+        .unwrap_or_else(|_| "unknown".into())
+}