feat(agent v0.1.6): métriques réseau enrichies + hardware dmidecode

- Nouveaux types payload: NetworkInterface, HardwareInfo
- Config: slow_daily_time (HH:MM), network_info, hardware_info
- Module network_info: interfaces locales, type ETH/WIFI, speed, MAC, WoL, iperf3
- Module hardware: dmidecode (carte mère, CPU, slots RAM, type/vitesse)
- Scheduler: collecte au démarrage + 1×/jour à l'heure configurée
- install.sh: ajout iperf3, dmidecode dans paquets

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

agent/src/payload.rs

@@ -19,6 +19,29 @@ pub struct AgentMetrics {
     pub network_tx: Option<u64>,
     pub temperature: Option<f32>,
     pub smart: Option<Vec<SmartMetrics>>,
+    pub network_info: Option<Vec<NetworkInterface>>,
+    pub hardware_info: Option<HardwareInfo>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, Default)]
+pub struct NetworkInterface {
+    pub name: String,
+    pub if_type: String,
+    pub speed_mbps: Option<i64>,
+    pub mac: String,
+    pub wol: Option<bool>,
+    pub iperf_mbps: Option<f64>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, Default)]
+pub struct HardwareInfo {
+    pub motherboard_vendor: Option<String>,
+    pub motherboard_model: Option<String>,
+    pub cpu_model: Option<String>,
+    pub ram_type: Option<String>,
+    pub ram_speed_mhz: Option<i64>,
+    pub ram_slots_used: Option<i64>,
+    pub ram_slots_total: Option<i64>,
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone)]