feat: suppression agent, RAM en Go, métriques par défaut (cpu/mem/disk/smart)

- API DELETE /api/agents/{id} — supprime agent + métriques + config + icône
- Bouton poubelle sur chaque tuile + dialog de confirmation
- RAM : affichage "utilisé/total" en Go (ex: 6.2Go/8.0Go) au lieu du %
- Config agent par défaut : cpu, memory, disk, smart activés (UDP)
- DefaultAgentConfig() dans models pour les nouveaux agents

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

server/db/db.go

@@ -238,6 +238,20 @@ func (d *DB) MarkOffline(timeoutSec int64) error {
 	return err
 }
 
+func (d *DB) DeleteAgent(agentID string) error {
+	for _, q := range []string{
+		`DELETE FROM metrics WHERE agent_id = ?`,
+		`DELETE FROM agent_configs WHERE agent_id = ?`,
+		`DELETE FROM agent_icons WHERE agent_id = ?`,
+		`DELETE FROM agents WHERE id = ?`,
+	} {
+		if _, err := d.conn.Exec(q, agentID); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 // MarkOfflineAndGetIDs marque les agents inactifs et retourne leurs IDs.
 func (d *DB) MarkOfflineAndGetIDs(timeoutSec int64) ([]string, error) {
 	cutoff := time.Now().Unix() - timeoutSec

server/handlers/agents.go

@@ -3,6 +3,7 @@ package handlers
 import (
 	"encoding/json"
 	"net/http"
+	"strings"
 
 	"github.com/user/nanometrics/server/db"
 )
@@ -18,3 +19,19 @@ func AgentsHandler(database *db.DB) http.HandlerFunc {
 		json.NewEncoder(w).Encode(agents)
 	}
 }
+
+func DeleteAgentHandler(database *db.DB) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		parts := strings.Split(strings.Trim(r.URL.Path, "/"), "/")
+		if len(parts) < 3 {
+			http.Error(w, "invalid path", 400)
+			return
+		}
+		agentID := parts[2]
+		if err := database.DeleteAgent(agentID); err != nil {
+			http.Error(w, err.Error(), 500)
+			return
+		}
+		w.WriteHeader(http.StatusNoContent)
+	}
+}

server/handlers/config.go

@@ -26,7 +26,7 @@ func AgentConfigHandler(database *db.DB, pushConfig func(agentID string, cfg *mo
 				return
 			}
 			if cfg == nil {
-				cfg = &models.AgentConfig{}
+				cfg = models.DefaultAgentConfig()
 			}
 			w.Header().Set("Content-Type", "application/json")
 			json.NewEncoder(w).Encode(cfg)

server/main.go

@@ -110,6 +110,8 @@ func main() {
 			handlers.IconUploadHandler(database)(w, r)
 		case endsWith(r.URL.Path, "/icon") && r.Method == http.MethodGet:
 			handlers.IconGetHandler(database)(w, r)
+		case r.Method == http.MethodDelete:
+			handlers.DeleteAgentHandler(database)(w, r)
 		default:
 			http.NotFound(w, r)
 		}

server/models/models.go

@@ -88,6 +88,20 @@ type ServerConfig struct {
 	PopupDetailH     int  `json:"popup_detail_h"`
 }
 
+func DefaultAgentConfig() *AgentConfig {
+	on := MetricProto{UDP: true, MQTT: false}
+	return &AgentConfig{
+		Protocols: ProtocolsConfig{UDP: UDPConfig{Enabled: true}},
+		Metrics: MetricsConfig{
+			CPU:     on,
+			Memory:  on,
+			Disk:    on,
+			Smart:   on,
+			Uptime:  on,
+		},
+	}
+}
+
 func DefaultServerConfig() ServerConfig {
 	return ServerConfig{
 		TileMinWidth: 220, FontSize: 13,