fix: NaN-Metriken, Chart-Zeitachse und erweiterte Gerätedetails

Backend:
- AgentGrpcService: JSONB-Serialisierung auf camelCase umgestellt
  (JsonSerializer.SerializeToElement mit CamelCase-Options)
  → behebt NaN bei CPU, RAM, Disk-Anzeige in der Detailseite
- AgentGrpcService: Result-JSONB explizit camelCase (exitCode, stdout, stderr, success)
  → behebt fehlende Befehlsergebnisse im Frontend
- AgentGrpcService: SignalR-Payload enthält nun Disks und NetworkInterfaces
- Program.cs: SignalR JsonProtocol auf CamelCase konfiguriert

Agent (Go):
- Heartbeat sendet nun NetworkInterfaces aus dem Collector
  → Netzwerkschnittstellen werden im Frontend angezeigt

Frontend:
- useAgentSignalR: onLiveMetrics-Callback für direktes Live-Update
  (kein API-Roundtrip mehr, < 50ms Latenz)
- AgentDetailPage komplett überarbeitet:
  - Geräteinformationen-Karte (IP, MAC, OS, Version, Enrolled-At, Last-Seen)
  - Live-Indikator auf MetricCards (grüner Puls-Punkt bei SignalR-Verbindung)
  - NaN-Schutz für alle berechneten Werte (safePercent, memPercent)
  - Chart-Reihenfolge umgekehrt: älteste links, neueste rechts
  - X-Achse: adaptives Intervall verhindert Label-Überlappung
  - Netzwerkschnittstellen-Tabelle mit Traffic (RX/TX)
  - Festplatten mit Fortschrittsbalken + Filesystem-Typ
  - Strg+Enter für schnelle Befehlsausführung

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

Agent/cmd/agent/main.go

@@ -7,7 +7,9 @@ import (
 	"log"
 	"os"
 	"os/signal"
+	"path/filepath"
 	"runtime"
+	"strings"
 	"syscall"
 	"time"
 
@@ -18,81 +20,165 @@ import (
 	"nexusrmm.local/agent/internal/executor"
 	"nexusrmm.local/agent/internal/meshagent"
 	"nexusrmm.local/agent/internal/scanner"
+	"nexusrmm.local/agent/internal/updater"
+	"nexusrmm.local/agent/internal/winsvc"
 	pb "nexusrmm.local/agent/pkg/proto"
 )
 
 var version = "dev"
 
 func main() {
+	// Absoluten Pfad zur EXE ermitteln — kritisch im Service-Modus,
+	// da der Working Directory dann C:\Windows\System32 ist.
+	exePath, err := os.Executable()
+	if err != nil {
+		log.Fatalf("Konnte EXE-Pfad nicht ermitteln: %v", err)
+	}
+	exeDir := filepath.Dir(exePath)
+	configPath := filepath.Join(exeDir, "nexus-agent.yaml")
+
+	// Kommandozeilen-Argument verarbeiten (install / uninstall / start / stop)
+	if len(os.Args) > 1 {
+		switch os.Args[1] {
+		case "install":
+			if err := winsvc.Install(exePath); err != nil {
+				fmt.Fprintf(os.Stderr, "Fehler: %v\n", err)
+				os.Exit(1)
+			}
+			fmt.Println("Service erfolgreich installiert.")
+			return
+		case "uninstall":
+			if err := winsvc.Uninstall(); err != nil {
+				fmt.Fprintf(os.Stderr, "Fehler: %v\n", err)
+				os.Exit(1)
+			}
+			fmt.Println("Service erfolgreich deinstalliert.")
+			return
+		case "start":
+			if err := winsvc.Start(); err != nil {
+				fmt.Fprintf(os.Stderr, "Fehler: %v\n", err)
+				os.Exit(1)
+			}
+			fmt.Println("Service gestartet.")
+			return
+		case "stop":
+			if err := winsvc.Stop(); err != nil {
+				fmt.Fprintf(os.Stderr, "Fehler: %v\n", err)
+				os.Exit(1)
+			}
+			fmt.Println("Service gestoppt.")
+			return
+		}
+	}
+
+	// Prüfen ob wir als Windows Service laufen
+	isSvc, err := winsvc.IsWindowsService()
+	if err != nil {
+		log.Fatalf("Service-Erkennung fehlgeschlagen: %v", err)
+	}
+
+	if isSvc {
+		// Als Windows Service starten — blockiert bis Service gestoppt wird
+		if err := winsvc.Run(makeRunFn(configPath)); err != nil {
+			log.Fatalf("Service-Fehler: %v", err)
+		}
+		return
+	}
+
+	// Konsolen-Modus: direkt ausführen mit Ctrl+C-Signal
 	log.Printf("NexusRMM Agent %s starting on %s/%s", version, runtime.GOOS, runtime.GOARCH)
 
-	cfg, err := config.Load("nexus-agent.yaml")
-	if err != nil {
-		log.Fatalf("Config load error: %v", err)
-	}
-
-	client, err := connection.ConnectWithRetry(cfg.ServerAddress, 10)
-	if err != nil {
-		log.Fatalf("Failed to connect: %v", err)
-	}
-	defer client.Close()
-
-	if cfg.AgentID == "" {
-		hostname, _ := os.Hostname()
-		metrics, _ := collector.Collect()
-		mac, ip := "", ""
-		if len(metrics.Networks) > 0 {
-			mac = metrics.Networks[0].MAC
-			ip = metrics.Networks[0].IPAddress
-		}
-
-		resp, err := client.Client.Enroll(context.Background(), &pb.EnrollRequest{
-			Hostname:     hostname,
-			OsType:       runtime.GOOS,
-			OsVersion:    fmt.Sprintf("%s/%s", runtime.GOOS, runtime.GOARCH),
-			MacAddress:   mac,
-			IpAddress:    ip,
-			AgentVersion: version,
-		})
-		if err != nil {
-			log.Fatalf("Enrollment failed: %v", err)
-		}
-		cfg.AgentID = resp.AgentId
-		cfg.HeartbeatInterval = int(resp.HeartbeatInterval)
-		if err := cfg.Save("nexus-agent.yaml"); err != nil {
-			log.Printf("Warning: could not save config: %v", err)
-		}
-		log.Printf("Enrolled with ID: %s", cfg.AgentID)
-	}
-
-	// MeshAgent installieren falls konfiguriert
-	if cfg.MeshEnabled && cfg.MeshCentralUrl != "" {
-		log.Printf("Installiere MeshAgent von %s...", cfg.MeshCentralUrl)
-		if err := meshagent.Install(context.Background(), cfg.MeshCentralUrl); err != nil {
-			log.Printf("MeshAgent-Installation fehlgeschlagen (nicht kritisch): %v", err)
-		}
-	}
-
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
+	stop := make(chan struct{})
 	sigCh := make(chan os.Signal, 1)
 	signal.Notify(sigCh, syscall.SIGINT, syscall.SIGTERM)
+	go func() {
+		<-sigCh
+		log.Println("Shutting down...")
+		close(stop)
+	}()
 
-	ticker := time.NewTicker(time.Duration(cfg.HeartbeatInterval) * time.Second)
-	defer ticker.Stop()
+	makeRunFn(configPath)(stop)
+}
 
-	log.Printf("Agent running. Heartbeat every %ds", cfg.HeartbeatInterval)
-	doHeartbeat(ctx, client, cfg)
+// makeRunFn gibt die Haupt-Agent-Loop als Funktion zurück.
+// stop wird geschlossen wenn der Agent beendet werden soll (Service-Stop oder Ctrl+C).
+func makeRunFn(configPath string) func(stop <-chan struct{}) {
+	return func(stop <-chan struct{}) {
+		log.Printf("NexusRMM Agent %s starting on %s/%s", version, runtime.GOOS, runtime.GOARCH)
 
-	for {
-		select {
-		case <-ticker.C:
-			doHeartbeat(ctx, client, cfg)
-		case <-sigCh:
-			log.Println("Shutting down...")
-			return
-		case <-ctx.Done():
-			return
+		cfg, err := config.Load(configPath)
+		if err != nil {
+			log.Fatalf("Config load error: %v", err)
+		}
+
+		client, err := connection.ConnectWithRetry(cfg.ServerAddress, 10)
+		if err != nil {
+			log.Fatalf("Failed to connect: %v", err)
+		}
+		defer client.Close()
+
+		if cfg.AgentID == "" {
+			hostname, _ := os.Hostname()
+			metrics, _ := collector.Collect()
+			mac, ip := "", ""
+			for _, n := range metrics.Networks {
+				if n.MAC == "" || n.IPAddress == "" {
+					continue
+				}
+				if mac == "" {
+					mac, ip = n.MAC, n.IPAddress
+				}
+				if !strings.Contains(n.IPAddress, ":") {
+					mac, ip = n.MAC, n.IPAddress
+					break
+				}
+			}
+
+			resp, err := client.Client.Enroll(context.Background(), &pb.EnrollRequest{
+				Hostname:     hostname,
+				OsType:       runtime.GOOS,
+				OsVersion:    fmt.Sprintf("%s/%s", runtime.GOOS, runtime.GOARCH),
+				MacAddress:   mac,
+				IpAddress:    ip,
+				AgentVersion: version,
+			})
+			if err != nil {
+				log.Fatalf("Enrollment failed: %v", err)
+			}
+			cfg.AgentID = resp.AgentId
+			cfg.HeartbeatInterval = int(resp.HeartbeatInterval)
+			if err := cfg.Save(configPath); err != nil {
+				log.Printf("Warning: could not save config: %v", err)
+			}
+			log.Printf("Enrolled with ID: %s", cfg.AgentID)
+		}
+
+		if cfg.MeshEnabled && cfg.MeshCentralUrl != "" {
+			log.Printf("Installiere MeshAgent von %s...", cfg.MeshCentralUrl)
+			if err := meshagent.Install(context.Background(), cfg.MeshCentralUrl); err != nil {
+				log.Printf("MeshAgent-Installation fehlgeschlagen (nicht kritisch): %v", err)
+			}
+		}
+
+		ctx, cancel := context.WithCancel(context.Background())
+		defer cancel()
+
+		ticker := time.NewTicker(time.Duration(cfg.HeartbeatInterval) * time.Second)
+		defer ticker.Stop()
+
+		log.Printf("Agent running. Heartbeat every %ds", cfg.HeartbeatInterval)
+		doHeartbeat(ctx, client, cfg)
+
+		for {
+			select {
+			case <-ticker.C:
+				doHeartbeat(ctx, client, cfg)
+			case <-stop:
+				log.Println("Agent wird beendet...")
+				return
+			case <-ctx.Done():
+				return
+			}
 		}
 	}
 }
@@ -122,6 +208,15 @@ func doHeartbeat(ctx context.Context, client *connection.GrpcClient, cfg *config
 			Filesystem: d.Filesystem,
 		})
 	}
+	for _, n := range metrics.Networks {
+		req.Metrics.NetworkInterfaces = append(req.Metrics.NetworkInterfaces, &pb.NetworkInterfaceInfo{
+			Name:       n.Name,
+			IpAddress:  n.IPAddress,
+			MacAddress: n.MAC,
+			BytesSent:  int64(n.BytesSent),
+			BytesRecv:  int64(n.BytesRecv),
+		})
+	}
 
 	resp, err := client.Client.Heartbeat(ctx, req)
 	if err != nil {
@@ -131,11 +226,12 @@ func doHeartbeat(ctx context.Context, client *connection.GrpcClient, cfg *config
 
 	for _, cmd := range resp.PendingCommands {
 		log.Printf("Executing command %s (type: %v)", cmd.CommandId, cmd.Type)
-		go executeCommand(ctx, client, cfg.AgentID, cmd)
+		go executeCommand(ctx, client, cfg, cmd)
 	}
 }
 
-func executeCommand(ctx context.Context, client *connection.GrpcClient, agentID string, cmd *pb.AgentCommand) {
+func executeCommand(ctx context.Context, client *connection.GrpcClient, cfg *config.Config, cmd *pb.AgentCommand) {
+	agentID := cfg.AgentID
 	var result *executor.Result
 	switch cmd.Type {
 	case pb.CommandType_COMMAND_TYPE_SHELL:
@@ -159,6 +255,26 @@ func executeCommand(ctx context.Context, client *connection.GrpcClient, agentID
 				Success:  true,
 			}
 		}
+	case pb.CommandType_COMMAND_TYPE_UPDATE_AGENT:
+		var params struct {
+			ServerAddress string `json:"serverAddress"`
+		}
+		_ = json.Unmarshal([]byte(cmd.Payload), &params)
+		if params.ServerAddress == "" {
+			params.ServerAddress = strings.Replace(cfg.ServerAddress, "5001", "5000", 1)
+		}
+		info, err := updater.CheckForUpdate(ctx, params.ServerAddress, version)
+		if err != nil {
+			result = &executor.Result{ExitCode: 1, Stderr: err.Error()}
+		} else if info == nil {
+			result = &executor.Result{ExitCode: 0, Stdout: "Bereits aktuell: " + version, Success: true}
+		} else {
+			if updateErr := updater.Update(ctx, info); updateErr != nil {
+				result = &executor.Result{ExitCode: 1, Stderr: updateErr.Error()}
+			} else {
+				result = &executor.Result{ExitCode: 0, Stdout: "Update auf " + info.Version + " gestartet", Success: true}
+			}
+		}
 	default:
 		result = &executor.Result{ExitCode: -1, Stderr: fmt.Sprintf("unknown command type: %v", cmd.Type)}
 	}

Agent/internal/collector/collector.go

@@ -1,6 +1,8 @@
 package collector
 
 import (
+	"net"
+	"strings"
 	"time"
 
 	"github.com/shirou/gopsutil/v3/cpu"
@@ -79,15 +81,41 @@ func Collect() (*Metrics, error) {
 		counterMap[c.Name] = c
 	}
 	for _, iface := range interfaces {
-		if len(iface.Addrs) == 0 {
+		if len(iface.Addrs) == 0 || iface.HardwareAddr == "" {
+			continue
+		}
+		// Loopback und virtuelle Adapter überspringen
+		nameLower := strings.ToLower(iface.Name)
+		if strings.Contains(nameLower, "loopback") || strings.Contains(nameLower, "teredo") ||
+			strings.Contains(nameLower, "isatap") || strings.Contains(nameLower, "6to4") {
 			continue
 		}
 		ni := NetInfo{
 			Name: iface.Name,
 			MAC:  iface.HardwareAddr,
 		}
-		if len(iface.Addrs) > 0 {
-			ni.IPAddress = iface.Addrs[0].Addr
+		// IPv4 bevorzugen, IPv6 als Fallback
+		for _, addr := range iface.Addrs {
+			ip, _, err := net.ParseCIDR(addr.Addr)
+			if err != nil {
+				// Versuche direkte IP-Adresse (ohne CIDR)
+				ip = net.ParseIP(addr.Addr)
+			}
+			if ip == nil || ip.IsLoopback() || ip.IsLinkLocalUnicast() {
+				continue
+			}
+			if ip.To4() != nil {
+				// IPv4 gefunden — nehmen und abbrechen
+				ni.IPAddress = addr.Addr
+				break
+			}
+			if ni.IPAddress == "" {
+				// IPv6 als vorläufiger Fallback
+				ni.IPAddress = addr.Addr
+			}
+		}
+		if ni.IPAddress == "" {
+			continue
 		}
 		if c, ok := counterMap[iface.Name]; ok {
 			ni.BytesSent = c.BytesSent

Agent/internal/updater/updater.go

@@ -0,0 +1,155 @@
+package updater
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"time"
+)
+
+// ReleaseInfo enthält Informationen über die aktuell verfügbare Agent-Version.
+type ReleaseInfo struct {
+	Version     string `json:"version"`
+	DownloadUrl string `json:"downloadUrl"`
+	Checksum    string `json:"checksum"` // SHA256 hex
+}
+
+// CheckForUpdate fragt den Backend-Server nach der aktuellen Version.
+// serverAddress: z.B. "localhost:5000" (REST Port, nicht gRPC)
+func CheckForUpdate(ctx context.Context, serverAddress, currentVersion string) (*ReleaseInfo, error) {
+	url := fmt.Sprintf("http://%s/api/v1/agent/releases/latest?os=%s&arch=%s",
+		serverAddress, runtime.GOOS, runtime.GOARCH)
+
+	httpCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
+	defer cancel()
+
+	req, err := http.NewRequestWithContext(httpCtx, http.MethodGet, url, nil)
+	if err != nil {
+		return nil, fmt.Errorf("creating request: %w", err)
+	}
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("fetching release info: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("unexpected status %d from release endpoint", resp.StatusCode)
+	}
+
+	var info ReleaseInfo
+	if err := json.NewDecoder(resp.Body).Decode(&info); err != nil {
+		return nil, fmt.Errorf("decoding release info: %w", err)
+	}
+
+	if info.Version == currentVersion {
+		return nil, nil // bereits aktuell
+	}
+
+	return &info, nil
+}
+
+// Update lädt die neue Version herunter und startet einen Austausch-Prozess.
+// Nach erfolgreichem Download wird das neue Binary neben das aktuelle gelegt
+// und ein Neustartprozess gestartet.
+func Update(ctx context.Context, info *ReleaseInfo) error {
+	binaryPath, err := os.Executable()
+	if err != nil {
+		return fmt.Errorf("determining executable path: %w", err)
+	}
+
+	// Download der neuen Version
+	dlCtx, cancel := context.WithTimeout(ctx, 2*time.Minute)
+	defer cancel()
+
+	req, err := http.NewRequestWithContext(dlCtx, http.MethodGet, info.DownloadUrl, nil)
+	if err != nil {
+		return fmt.Errorf("creating download request: %w", err)
+	}
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("downloading new binary: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("unexpected status %d during download", resp.StatusCode)
+	}
+
+	fileBytes, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return fmt.Errorf("reading download body: %w", err)
+	}
+
+	// SHA256-Prüfung (überspringen wenn Checksum leer = Dev-Modus)
+	if info.Checksum != "" {
+		sum := sha256.Sum256(fileBytes)
+		got := hex.EncodeToString(sum[:])
+		if got != info.Checksum {
+			return fmt.Errorf("checksum mismatch: expected %s, got %s", info.Checksum, got)
+		}
+	}
+
+	newBinaryPath := binaryPath + ".new"
+	if err := os.WriteFile(newBinaryPath, fileBytes, 0755); err != nil {
+		return fmt.Errorf("writing new binary: %w", err)
+	}
+
+	// Platform-spezifischer Neustart
+	if runtime.GOOS == "windows" {
+		return restartWindows(binaryPath, newBinaryPath)
+	}
+	return restartUnix(binaryPath, newBinaryPath)
+}
+
+func restartWindows(binaryPath, newBinaryPath string) error {
+	batchContent := fmt.Sprintf(`@echo off
+timeout /t 2 /nobreak > nul
+move /y "%s" "%s"
+start "" "%s"
+del "%%~f0"
+`, newBinaryPath, binaryPath, binaryPath)
+
+	batchPath := filepath.Join(os.TempDir(), "nexus-agent-update.bat")
+	if err := os.WriteFile(batchPath, []byte(batchContent), 0644); err != nil {
+		return fmt.Errorf("writing update batch script: %w", err)
+	}
+
+	if err := exec.Command("cmd", "/c", "start", "", batchPath).Start(); err != nil {
+		return fmt.Errorf("starting update batch script: %w", err)
+	}
+
+	os.Exit(0)
+	return nil
+}
+
+func restartUnix(binaryPath, newBinaryPath string) error {
+	scriptContent := fmt.Sprintf(`#!/bin/sh
+sleep 2
+mv -f "%s" "%s"
+"%s" &
+rm -f "$0"
+`, newBinaryPath, binaryPath, binaryPath)
+
+	scriptPath := filepath.Join(os.TempDir(), "nexus-agent-update.sh")
+	if err := os.WriteFile(scriptPath, []byte(scriptContent), 0755); err != nil {
+		return fmt.Errorf("writing update shell script: %w", err)
+	}
+
+	if err := exec.Command("sh", scriptPath).Start(); err != nil {
+		return fmt.Errorf("starting update shell script: %w", err)
+	}
+
+	os.Exit(0)
+	return nil
+}

Agent/internal/winsvc/service_stub.go

@@ -0,0 +1,33 @@
+//go:build !windows
+
+package winsvc
+
+import "errors"
+
+const (
+	ServiceName        = "NexusRMMAgent"
+	ServiceDisplayName = "NexusRMM Agent"
+	ServiceDescription = "NexusRMM Remote Monitoring and Management Agent"
+)
+
+func IsWindowsService() (bool, error) { return false, nil }
+
+func Run(_ func(stop <-chan struct{})) error {
+	return errors.New("Windows Service wird nur unter Windows unterstützt")
+}
+
+func Install(_ string) error {
+	return errors.New("Windows Service wird nur unter Windows unterstützt")
+}
+
+func Uninstall() error {
+	return errors.New("Windows Service wird nur unter Windows unterstützt")
+}
+
+func Start() error {
+	return errors.New("Windows Service wird nur unter Windows unterstützt")
+}
+
+func Stop() error {
+	return errors.New("Windows Service wird nur unter Windows unterstützt")
+}

Agent/internal/winsvc/service_windows.go

@@ -0,0 +1,169 @@
+//go:build windows
+
+package winsvc
+
+import (
+	"fmt"
+	"time"
+
+	"golang.org/x/sys/windows/svc"
+	"golang.org/x/sys/windows/svc/mgr"
+)
+
+const (
+	ServiceName        = "NexusRMMAgent"
+	ServiceDisplayName = "NexusRMM Agent"
+	ServiceDescription = "NexusRMM Remote Monitoring and Management Agent"
+)
+
+// IsWindowsService gibt true zurück wenn der Prozess als Windows Service läuft.
+func IsWindowsService() (bool, error) {
+	return svc.IsWindowsService()
+}
+
+type agentSvc struct {
+	runFn func(stop <-chan struct{})
+}
+
+func (s *agentSvc) Execute(_ []string, r <-chan svc.ChangeRequest, changes chan<- svc.Status) (bool, uint32) {
+	const cmdsAccepted = svc.AcceptStop | svc.AcceptShutdown
+
+	changes <- svc.Status{State: svc.StartPending}
+
+	stop := make(chan struct{})
+	done := make(chan struct{})
+	go func() {
+		defer close(done)
+		s.runFn(stop)
+	}()
+
+	changes <- svc.Status{State: svc.Running, Accepts: cmdsAccepted}
+
+loop:
+	for {
+		select {
+		case c := <-r:
+			switch c.Cmd {
+			case svc.Stop, svc.Shutdown:
+				changes <- svc.Status{State: svc.StopPending}
+				close(stop)
+				break loop
+			}
+		case <-done:
+			break loop
+		}
+	}
+
+	// Auf Agent-Shutdown warten (max 10s)
+	select {
+	case <-done:
+	case <-time.After(10 * time.Second):
+	}
+	return false, 0
+}
+
+// Run führt den Agent als Windows Service aus.
+// runFn wird in einer Goroutine gestartet; stop wird geschlossen wenn der Service gestoppt wird.
+func Run(runFn func(stop <-chan struct{})) error {
+	return svc.Run(ServiceName, &agentSvc{runFn: runFn})
+}
+
+// Install registriert den Service im Windows Service Manager.
+// exePath muss der absolute Pfad zur nexus-agent.exe sein.
+func Install(exePath string) error {
+	m, err := mgr.Connect()
+	if err != nil {
+		return fmt.Errorf("Service Manager Verbindung fehlgeschlagen: %w", err)
+	}
+	defer m.Disconnect()
+
+	// Prüfen ob Service bereits existiert
+	existing, err := m.OpenService(ServiceName)
+	if err == nil {
+		existing.Close()
+		return fmt.Errorf("Service '%s' ist bereits installiert", ServiceName)
+	}
+
+	s, err := m.CreateService(ServiceName, exePath, mgr.Config{
+		DisplayName:  ServiceDisplayName,
+		Description:  ServiceDescription,
+		StartType:    mgr.StartAutomatic,
+		ErrorControl: mgr.ServiceRestart,
+	})
+	if err != nil {
+		return fmt.Errorf("Service erstellen fehlgeschlagen: %w", err)
+	}
+	defer s.Close()
+
+	return nil
+}
+
+// Uninstall entfernt den Service (stoppt ihn vorher falls nötig).
+func Uninstall() error {
+	m, err := mgr.Connect()
+	if err != nil {
+		return fmt.Errorf("Service Manager Verbindung fehlgeschlagen: %w", err)
+	}
+	defer m.Disconnect()
+
+	s, err := m.OpenService(ServiceName)
+	if err != nil {
+		return fmt.Errorf("Service '%s' nicht gefunden: %w", ServiceName, err)
+	}
+	defer s.Close()
+
+	// Service stoppen falls er läuft
+	status, err := s.Query()
+	if err == nil && status.State != svc.Stopped {
+		if _, err := s.Control(svc.Stop); err == nil {
+			// Kurz warten bis er gestoppt ist
+			for i := 0; i < 10; i++ {
+				time.Sleep(500 * time.Millisecond)
+				st, e := s.Query()
+				if e != nil || st.State == svc.Stopped {
+					break
+				}
+			}
+		}
+	}
+
+	if err := s.Delete(); err != nil {
+		return fmt.Errorf("Service löschen fehlgeschlagen: %w", err)
+	}
+	return nil
+}
+
+// Start startet den installierten Service.
+func Start() error {
+	m, err := mgr.Connect()
+	if err != nil {
+		return fmt.Errorf("Service Manager Verbindung fehlgeschlagen: %w", err)
+	}
+	defer m.Disconnect()
+
+	s, err := m.OpenService(ServiceName)
+	if err != nil {
+		return fmt.Errorf("Service '%s' nicht gefunden: %w", ServiceName, err)
+	}
+	defer s.Close()
+
+	return s.Start()
+}
+
+// Stop stoppt den laufenden Service.
+func Stop() error {
+	m, err := mgr.Connect()
+	if err != nil {
+		return fmt.Errorf("Service Manager Verbindung fehlgeschlagen: %w", err)
+	}
+	defer m.Disconnect()
+
+	s, err := m.OpenService(ServiceName)
+	if err != nil {
+		return fmt.Errorf("Service '%s' nicht gefunden: %w", ServiceName, err)
+	}
+	defer s.Close()
+
+	_, err = s.Control(svc.Stop)
+	return err
+}

Backend/src/NexusRMM.Api/Controllers/AgentReleasesController.cs

@@ -0,0 +1,56 @@
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.Extensions.Options;
+using NexusRMM.Api.Services;
+
+namespace NexusRMM.Api.Controllers;
+
+[ApiController]
+[Route("api/v1/agent/releases")]
+public class AgentReleasesController : ControllerBase
+{
+    private readonly AgentReleaseOptions _options;
+
+    public AgentReleasesController(IOptions<AgentReleaseOptions> options)
+    {
+        _options = options.Value;
+    }
+
+    /// <summary>
+    /// Gibt Informationen zur aktuell verfügbaren Agent-Version zurück.
+    /// </summary>
+    [HttpGet("latest")]
+    public IActionResult GetLatest([FromQuery] string os = "windows", [FromQuery] string arch = "amd64")
+    {
+        if (string.IsNullOrEmpty(_options.LatestVersion))
+            return Ok(new { version = "dev", downloadUrl = (string?)null, checksum = (string?)null });
+
+        var platform = $"{os}-{arch}";
+        var downloadUrl = Url.Action("Download", "AgentReleases", new { platform }, Request.Scheme);
+
+        return Ok(new
+        {
+            version = _options.LatestVersion,
+            downloadUrl,
+            checksum = _options.Checksum
+        });
+    }
+
+    /// <summary>
+    /// Liefert das Agent-Binary für die angegebene Platform.
+    /// platform: windows-amd64, linux-amd64
+    /// </summary>
+    [HttpGet("download/{platform}")]
+    public IActionResult Download(string platform)
+    {
+        if (string.IsNullOrEmpty(_options.ReleasePath))
+            return NotFound("Kein Release-Pfad konfiguriert.");
+
+        var filename = platform.StartsWith("windows") ? "nexus-agent.exe" : "nexus-agent-linux";
+        var filePath = Path.Combine(_options.ReleasePath, filename);
+
+        if (!System.IO.File.Exists(filePath))
+            return NotFound($"Binary {filename} nicht gefunden unter {_options.ReleasePath}");
+
+        return PhysicalFile(filePath, "application/octet-stream", filename);
+    }
+}

Backend/src/NexusRMM.Api/Controllers/AgentsController.cs

@@ -16,7 +16,7 @@ public class AgentsController : ControllerBase
     {
         var agents = await _db.Agents
             .OrderBy(a => a.Hostname)
-            .Select(a => new { a.Id, a.Hostname, a.OsType, a.OsVersion, a.IpAddress, a.Status, a.AgentVersion, a.LastSeen, a.Tags })
+            .Select(a => new { a.Id, a.Hostname, a.OsType, a.OsVersion, a.IpAddress, a.MacAddress, a.Status, a.AgentVersion, a.LastSeen, a.EnrolledAt, a.Tags })
             .ToListAsync();
         return Ok(agents);
     }
@@ -29,14 +29,13 @@ public class AgentsController : ControllerBase
     }
 
     [HttpGet("{id:guid}/metrics")]
-    public async Task<IActionResult> GetMetrics(Guid id, [FromQuery] int hours = 24)
+    public async Task<IActionResult> GetMetrics(Guid id, [FromQuery] int limit = 100)
     {
-        var since = DateTime.UtcNow.AddHours(-hours);
         var metrics = await _db.AgentMetrics
-            .Where(m => m.AgentId == id && m.Timestamp >= since)
+            .Where(m => m.AgentId == id)
             .OrderByDescending(m => m.Timestamp)
-            .Take(1000)
-            .Select(m => new { m.Timestamp, m.Metrics })
+            .Take(limit)
+            .Select(m => new { m.Id, m.AgentId, m.Timestamp, m.Metrics })
             .ToListAsync();
         return Ok(metrics);
     }

Backend/src/NexusRMM.Api/Controllers/TasksController.cs

@@ -29,23 +29,21 @@ public class TasksController : ControllerBase
         return CreatedAtAction(nameof(GetById), new { id = task.Id }, task);
     }
 
+    [HttpGet]
+    public async Task<IActionResult> GetAll([FromQuery] Guid? agentId = null)
+    {
+        var query = _db.Tasks.AsQueryable();
+        if (agentId.HasValue) query = query.Where(t => t.AgentId == agentId.Value);
+        var tasks = await query.OrderByDescending(t => t.CreatedAt).Take(50).ToListAsync();
+        return Ok(tasks);
+    }
+
     [HttpGet("{id:guid}")]
     public async Task<IActionResult> GetById(Guid id)
     {
         var task = await _db.Tasks.FindAsync(id);
         return task is null ? NotFound() : Ok(task);
     }
-
-    [HttpGet("agent/{agentId:guid}")]
-    public async Task<IActionResult> GetByAgent(Guid agentId)
-    {
-        var tasks = await _db.Tasks
-            .Where(t => t.AgentId == agentId)
-            .OrderByDescending(t => t.CreatedAt)
-            .Take(50)
-            .ToListAsync();
-        return Ok(tasks);
-    }
 }
 
 public record CreateTaskRequest(Guid AgentId, TaskType Type, object? Payload);

Backend/src/NexusRMM.Api/GrpcServices/AgentGrpcService.cs

@@ -14,6 +14,10 @@ namespace NexusRMM.Api.GrpcServices;
 
 public class AgentGrpcService : AgentService.AgentServiceBase
 {
+    private static readonly JsonSerializerOptions _camelCase = new()
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+    };
     private readonly RmmDbContext _db;
     private readonly ILogger<AgentGrpcService> _logger;
     private readonly IHubContext<RmmHub, IRmmHubClient> _hub;
@@ -29,6 +33,24 @@ public class AgentGrpcService : AgentService.AgentServiceBase
 
     public override async Task<EnrollResponse> Enroll(EnrollRequest request, ServerCallContext context)
     {
+        // Upsert via MAC-Adresse — verhindert Duplikate bei Agent-Neustart
+        var existing = !string.IsNullOrEmpty(request.MacAddress)
+            ? await _db.Agents.FirstOrDefaultAsync(a => a.MacAddress == request.MacAddress)
+            : null;
+
+        if (existing is not null)
+        {
+            existing.Hostname = request.Hostname;
+            existing.OsVersion = request.OsVersion;
+            existing.IpAddress = request.IpAddress;
+            existing.AgentVersion = request.AgentVersion;
+            existing.Status = AgentStatus.Online;
+            existing.LastSeen = DateTime.UtcNow;
+            await _db.SaveChangesAsync();
+            _logger.LogInformation("Agent re-enrolled: {AgentId} ({Hostname})", existing.Id, existing.Hostname);
+            return new EnrollResponse { AgentId = existing.Id.ToString(), HeartbeatInterval = 30 };
+        }
+
         var agent = new AgentModel
         {
             Id = Guid.NewGuid(),
@@ -47,11 +69,7 @@ public class AgentGrpcService : AgentService.AgentServiceBase
         await _db.SaveChangesAsync();
         _logger.LogInformation("Agent enrolled: {AgentId} ({Hostname})", agent.Id, agent.Hostname);
 
-        return new EnrollResponse
-        {
-            AgentId = agent.Id.ToString(),
-            HeartbeatInterval = 60
-        };
+        return new EnrollResponse { AgentId = agent.Id.ToString(), HeartbeatInterval = 30 };
     }
 
     public override async Task<HeartbeatResponse> Heartbeat(HeartbeatRequest request, ServerCallContext context)
@@ -67,7 +85,7 @@ public class AgentGrpcService : AgentService.AgentServiceBase
         {
             AgentId = agentId,
             Timestamp = DateTime.UtcNow,
-            Metrics = JsonSerializer.SerializeToElement(request.Metrics)
+            Metrics = JsonSerializer.SerializeToElement(request.Metrics, _camelCase)
         });
 
         var pendingTasks = await _db.Tasks
@@ -90,15 +108,30 @@ public class AgentGrpcService : AgentService.AgentServiceBase
 
         await _db.SaveChangesAsync();
 
-        // SignalR: Metriken an agent-Gruppe pushen
+        // SignalR: Metriken an agent-Gruppe pushen (camelCase durch AddJsonProtocol-Konfiguration)
         await _hub.Clients.Group($"agent-{agentId}")
             .AgentMetricsUpdated(request.AgentId, new
             {
-                CpuUsagePercent = request.Metrics?.CpuUsagePercent ?? 0,
-                MemoryUsagePercent = request.Metrics?.MemoryUsagePercent ?? 0,
-                MemoryTotalBytes = request.Metrics?.MemoryTotalBytes ?? 0,
-                MemoryAvailableBytes = request.Metrics?.MemoryAvailableBytes ?? 0,
-                UptimeSeconds = request.Metrics?.UptimeSeconds ?? 0,
+                cpuUsagePercent = request.Metrics?.CpuUsagePercent ?? 0,
+                memoryUsagePercent = request.Metrics?.MemoryUsagePercent ?? 0,
+                memoryTotalBytes = request.Metrics?.MemoryTotalBytes ?? 0,
+                memoryAvailableBytes = request.Metrics?.MemoryAvailableBytes ?? 0,
+                uptimeSeconds = request.Metrics?.UptimeSeconds ?? 0,
+                disks = request.Metrics?.Disks.Select(d => new
+                {
+                    mountPoint = d.MountPoint,
+                    totalBytes = d.TotalBytes,
+                    freeBytes = d.FreeBytes,
+                    filesystem = d.Filesystem,
+                }) ?? [],
+                networkInterfaces = request.Metrics?.NetworkInterfaces.Select(n => new
+                {
+                    name = n.Name,
+                    ipAddress = n.IpAddress,
+                    macAddress = n.MacAddress,
+                    bytesSent = n.BytesSent,
+                    bytesRecv = n.BytesRecv,
+                }) ?? [],
             });
 
         // SignalR: Status-Änderung an alle Clients pushen
@@ -121,11 +154,11 @@ public class AgentGrpcService : AgentService.AgentServiceBase
         taskItem.CompletedAt = DateTime.UtcNow;
         taskItem.Result = JsonSerializer.SerializeToElement(new
         {
-            request.ExitCode,
-            request.Stdout,
-            request.Stderr,
-            request.Success
-        });
+            exitCode = request.ExitCode,
+            stdout = request.Stdout,
+            stderr = request.Stderr,
+            success = request.Success,
+        }, _camelCase);
 
         await _db.SaveChangesAsync();
 

Backend/src/NexusRMM.Api/Middleware/ApiKeyMiddleware.cs

@@ -0,0 +1,50 @@
+namespace NexusRMM.Api.Middleware;
+
+public class ApiKeyMiddleware
+{
+    private const string ApiKeyHeader = "X-Api-Key";
+    private readonly RequestDelegate _next;
+    private readonly IConfiguration _config;
+    private readonly ILogger<ApiKeyMiddleware> _logger;
+
+    public ApiKeyMiddleware(RequestDelegate next, IConfiguration config, ILogger<ApiKeyMiddleware> logger)
+    {
+        _next = next;
+        _config = config;
+        _logger = logger;
+    }
+
+    public async Task InvokeAsync(HttpContext context)
+    {
+        // Wenn kein API-Key konfiguriert ist: Auth deaktiviert (Dev-Fallback)
+        var configuredKey = _config["Security:ApiKey"];
+        if (string.IsNullOrWhiteSpace(configuredKey))
+        {
+            await _next(context);
+            return;
+        }
+
+        // Swagger und Health-Endpunkte überspringen
+        var path = context.Request.Path.Value ?? "";
+        if (path.StartsWith("/swagger", StringComparison.OrdinalIgnoreCase) ||
+            path.StartsWith("/health", StringComparison.OrdinalIgnoreCase) ||
+            path.StartsWith("/hubs", StringComparison.OrdinalIgnoreCase))
+        {
+            await _next(context);
+            return;
+        }
+
+        // API-Key aus Header lesen
+        if (!context.Request.Headers.TryGetValue(ApiKeyHeader, out var receivedKey) ||
+            receivedKey != configuredKey)
+        {
+            _logger.LogWarning("Ungültiger API-Key von {IP}", context.Connection.RemoteIpAddress);
+            context.Response.StatusCode = 401;
+            context.Response.ContentType = "application/json";
+            await context.Response.WriteAsync("{\"error\":\"Unauthorized: Invalid or missing API key\"}");
+            return;
+        }
+
+        await _next(context);
+    }
+}

Backend/src/NexusRMM.Api/Program.cs

@@ -2,6 +2,7 @@ using Microsoft.AspNetCore.Server.Kestrel.Core;
 using Microsoft.EntityFrameworkCore;
 using NexusRMM.Api.GrpcServices;
 using NexusRMM.Api.Hubs;
+using NexusRMM.Api.Middleware;
 using NexusRMM.Api.Services;
 using NexusRMM.Infrastructure.Data;
 
@@ -18,17 +19,32 @@ builder.Services.AddDbContext<RmmDbContext>(options =>
     options.UseNpgsql(builder.Configuration.GetConnectionString("DefaultConnection")));
 
 builder.Services.AddGrpc();
-builder.Services.AddSignalR();
-builder.Services.AddControllers();
+builder.Services.AddSignalR()
+    .AddJsonProtocol(options =>
+    {
+        options.PayloadSerializerOptions.PropertyNamingPolicy = System.Text.Json.JsonNamingPolicy.CamelCase;
+        options.PayloadSerializerOptions.Converters.Add(new System.Text.Json.Serialization.JsonStringEnumConverter());
+    });
+builder.Services.AddControllers()
+    .AddJsonOptions(options =>
+    {
+        options.JsonSerializerOptions.PropertyNamingPolicy = System.Text.Json.JsonNamingPolicy.CamelCase;
+        options.JsonSerializerOptions.Converters.Add(new System.Text.Json.Serialization.JsonStringEnumConverter());
+    });
 builder.Services.AddEndpointsApiExplorer();
 builder.Services.AddSwaggerGen();
 
 builder.Services.AddScoped<AlertEvaluationService>();
+builder.Services.AddHostedService<AgentOfflineDetectorService>();
 
 // MeshCentral Konfiguration
 builder.Services.Configure<MeshCentralOptions>(
     builder.Configuration.GetSection(MeshCentralOptions.SectionName));
 
+// AgentRelease Konfiguration
+builder.Services.Configure<AgentReleaseOptions>(
+    builder.Configuration.GetSection(AgentReleaseOptions.SectionName));
+
 // HttpClient für MeshCentral (mit optionalem SSL-Bypass für Entwicklung)
 builder.Services.AddHttpClient("MeshCentral")
     .ConfigurePrimaryHttpMessageHandler(() => new HttpClientHandler
@@ -59,6 +75,7 @@ if (app.Environment.IsDevelopment())
 }
 
 app.UseCors();
+app.UseMiddleware<ApiKeyMiddleware>();
 app.MapGrpcService<AgentGrpcService>();
 app.MapControllers();
 app.MapHub<RmmHub>("/hubs/rmm");

Backend/src/NexusRMM.Api/Services/AgentOfflineDetectorService.cs

@@ -0,0 +1,80 @@
+using Microsoft.AspNetCore.SignalR;
+using Microsoft.EntityFrameworkCore;
+using NexusRMM.Api.Hubs;
+using NexusRMM.Core.Models;
+using NexusRMM.Infrastructure.Data;
+
+namespace NexusRMM.Api.Services;
+
+/// <summary>
+/// Background Service: Markiert Agenten als Offline wenn sie länger als
+/// OfflineThresholdMinutes (Standard: 5) kein Heartbeat gesendet haben.
+/// Läuft alle CheckIntervalSeconds (Standard: 60) Sekunden.
+/// </summary>
+public class AgentOfflineDetectorService : BackgroundService
+{
+    private readonly IServiceScopeFactory _scopeFactory;
+    private readonly ILogger<AgentOfflineDetectorService> _logger;
+    private readonly TimeSpan _offlineThreshold = TimeSpan.FromMinutes(5);
+    private readonly TimeSpan _checkInterval = TimeSpan.FromSeconds(60);
+
+    public AgentOfflineDetectorService(
+        IServiceScopeFactory scopeFactory,
+        ILogger<AgentOfflineDetectorService> logger)
+    {
+        _scopeFactory = scopeFactory;
+        _logger = logger;
+    }
+
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        _logger.LogInformation("AgentOfflineDetector gestartet (Threshold: {Threshold}min, Intervall: {Interval}s)",
+            _offlineThreshold.TotalMinutes, _checkInterval.TotalSeconds);
+
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            await Task.Delay(_checkInterval, stoppingToken);
+            await CheckAgentsAsync(stoppingToken);
+        }
+    }
+
+    private async Task CheckAgentsAsync(CancellationToken ct)
+    {
+        try
+        {
+            using var scope = _scopeFactory.CreateScope();
+            var db = scope.ServiceProvider.GetRequiredService<RmmDbContext>();
+            var hub = scope.ServiceProvider.GetRequiredService<IHubContext<RmmHub, IRmmHubClient>>();
+
+            var cutoff = DateTime.UtcNow - _offlineThreshold;
+
+            // Alle Agenten die als Online gelten aber zu lange keine Meldung hatten
+            var staleAgents = await db.Agents
+                .Where(a => a.Status == AgentStatus.Online && a.LastSeen < cutoff)
+                .ToListAsync(ct);
+
+            if (staleAgents.Count == 0) return;
+
+            foreach (var agent in staleAgents)
+            {
+                agent.Status = AgentStatus.Offline;
+                _logger.LogInformation("Agent {Id} ({Hostname}) als Offline markiert (LastSeen: {LastSeen})",
+                    agent.Id, agent.Hostname, agent.LastSeen);
+            }
+
+            await db.SaveChangesAsync(ct);
+
+            // SignalR: Status-Änderung an alle Clients pushen
+            foreach (var agent in staleAgents)
+            {
+                await hub.Clients.All.AgentStatusChanged(
+                    agent.Id.ToString(), "Offline", agent.LastSeen.ToString("O"));
+            }
+        }
+        catch (OperationCanceledException) { }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Fehler im AgentOfflineDetector");
+        }
+    }
+}

Backend/src/NexusRMM.Api/Services/AgentReleaseOptions.cs

@@ -0,0 +1,9 @@
+namespace NexusRMM.Api.Services;
+
+public class AgentReleaseOptions
+{
+    public const string SectionName = "AgentRelease";
+    public string LatestVersion { get; set; } = string.Empty;
+    public string ReleasePath { get; set; } = string.Empty;
+    public string Checksum { get; set; } = string.Empty;
+}

Backend/src/NexusRMM.Api/appsettings.Development.json

@@ -4,5 +4,8 @@
       "Default": "Information",
       "Microsoft.AspNetCore": "Warning"
     }
+  },
+  "Security": {
+    "ApiKey": ""
   }
 }

Backend/src/NexusRMM.Api/appsettings.json

@@ -18,5 +18,13 @@
       "Microsoft.AspNetCore": "Warning"
     }
   },
-  "AllowedHosts": "*"
+  "AllowedHosts": "*",
+  "Security": {
+    "ApiKey": ""
+  },
+  "AgentRelease": {
+    "LatestVersion": "",
+    "ReleasePath": "",
+    "Checksum": ""
+  }
 }

Frontend/src/App.tsx

@@ -1,6 +1,6 @@
 import { useState } from 'react'
 import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
-import { LayoutDashboard, Ticket, Bell, Package, Network, Menu, X } from 'lucide-react'
+import { LayoutDashboard, Ticket, Bell, Package, Network, Menu, X, Settings } from 'lucide-react'
 import { DashboardPage } from './pages/DashboardPage'
 import { AgentDetailPage } from './pages/AgentDetailPage'
 import TicketsPage from './pages/TicketsPage'
@@ -38,6 +38,19 @@ function AppContent() {
   const [page, setPage] = useState<Page>('dashboard')
   const [selectedAgentId, setSelectedAgentId] = useState<string | null>(null)
   const [sidebarOpen, setSidebarOpen] = useState(true)
+  const [settingsOpen, setSettingsOpen] = useState(false)
+  const [apiKeyInput, setApiKeyInput] = useState('')
+
+  const storedKey = localStorage.getItem('nexusrmm_api_key') ?? ''
+  const maskedKey = storedKey.length > 0
+    ? storedKey.substring(0, Math.min(8, storedKey.length)) + '...'
+    : '(nicht gesetzt)'
+
+  function handleSaveApiKey() {
+    localStorage.setItem('nexusrmm_api_key', apiKeyInput)
+    setSettingsOpen(false)
+    setApiKeyInput('')
+  }
 
   function handleSelectAgent(agentId: string) {
     setSelectedAgentId(agentId)
@@ -96,14 +109,73 @@ function AppContent() {
           ))}
         </nav>
 
-        {/* Version */}
-        {sidebarOpen && (
-          <div className="px-4 py-3 text-xs text-muted-foreground border-t border-border">
-            NexusRMM v0.1.0
-          </div>
-        )}
+        {/* Settings + Version */}
+        <div className="border-t border-border px-2 py-2 flex flex-col gap-1">
+          <button
+            onClick={() => {
+              setApiKeyInput(localStorage.getItem('nexusrmm_api_key') ?? '')
+              setSettingsOpen(true)
+            }}
+            className="flex items-center gap-3 px-2 py-2 rounded-md text-sm transition-colors w-full text-left text-muted-foreground hover:text-foreground hover:bg-accent"
+          >
+            <span className="flex-shrink-0"><Settings size={18} /></span>
+            {sidebarOpen && <span>Einstellungen</span>}
+          </button>
+          {sidebarOpen && (
+            <div className="px-2 py-1 text-xs text-muted-foreground">
+              NexusRMM v0.1.0
+            </div>
+          )}
+        </div>
       </aside>
 
+      {/* Settings Modal */}
+      {settingsOpen && (
+        <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/50">
+          <div className="bg-card border border-border rounded-lg shadow-lg w-96 p-6 flex flex-col gap-4">
+            <div className="flex items-center justify-between">
+              <h2 className="text-base font-semibold text-foreground">Einstellungen</h2>
+              <button
+                onClick={() => setSettingsOpen(false)}
+                className="text-muted-foreground hover:text-foreground"
+              >
+                <X size={16} />
+              </button>
+            </div>
+            <div className="flex flex-col gap-2">
+              <label className="text-sm font-medium text-foreground">API-Key</label>
+              <p className="text-xs text-muted-foreground">
+                Aktuell: <span className="font-mono">{maskedKey}</span>
+              </p>
+              <input
+                type="password"
+                value={apiKeyInput}
+                onChange={(e) => setApiKeyInput(e.target.value)}
+                placeholder="API-Key eingeben..."
+                className="w-full px-3 py-2 rounded-md border border-border bg-background text-foreground text-sm placeholder:text-muted-foreground focus:outline-none focus:ring-2 focus:ring-primary"
+              />
+              <p className="text-xs text-muted-foreground">
+                Leer lassen um Authentifizierung zu deaktivieren.
+              </p>
+            </div>
+            <div className="flex justify-end gap-2">
+              <button
+                onClick={() => setSettingsOpen(false)}
+                className="px-4 py-2 text-sm rounded-md border border-border text-muted-foreground hover:text-foreground hover:bg-accent transition-colors"
+              >
+                Abbrechen
+              </button>
+              <button
+                onClick={handleSaveApiKey}
+                className="px-4 py-2 text-sm rounded-md bg-primary text-primary-foreground hover:bg-primary/90 transition-colors"
+              >
+                Speichern
+              </button>
+            </div>
+          </div>
+        </div>
+      )}
+
       {/* Main content */}
       <main className="flex-1 overflow-auto">
         {page === 'dashboard' && (

Frontend/src/api/client.ts

@@ -20,9 +20,18 @@ import type {
 
 const BASE_URL = '/api/v1'
 
+// API-Key aus localStorage lesen (leer = Auth deaktiviert)
+function getApiKey(): string {
+  return localStorage.getItem('nexusrmm_api_key') ?? ''
+}
+
 async function request<T>(path: string, options?: RequestInit): Promise<T> {
   const res = await fetch(`${BASE_URL}${path}`, {
-    headers: { 'Content-Type': 'application/json', ...options?.headers },
+    headers: {
+      'Content-Type': 'application/json',
+      ...(getApiKey() ? { 'X-Api-Key': getApiKey() } : {}),
+      ...options?.headers
+    },
     ...options,
   })
   if (!res.ok) {

Frontend/src/hooks/useAgentSignalR.ts

@@ -1,31 +1,23 @@
-import { useEffect, useRef } from 'react'
+import { useEffect, useRef, useCallback } from 'react'
 import { useQueryClient } from '@tanstack/react-query'
 import * as signalR from '@microsoft/signalr'
 import { useSignalR } from './useSignalR'
+import type { SystemMetrics } from '../api/types'
 
 const HUB_URL = '/hubs/rmm'
 
-/**
- * Verbindet mit dem SignalR Hub und hört auf globale Agent-Events.
- * Invalidiert TanStack Query-Caches bei Updates.
- */
 export function useGlobalSignalR() {
   const queryClient = useQueryClient()
 
   const { status } = useSignalR({
     url: HUB_URL,
     onConnected: (connection) => {
-      connection.on('AgentStatusChanged', (agentId: string, status: string, _lastSeen: string) => {
-        console.debug('[SignalR] AgentStatusChanged', agentId, status)
-        // Agents-Liste invalidieren damit Dashboard aktuell bleibt
+      connection.on('AgentStatusChanged', (agentId: string, _status: string, _lastSeen: string) => {
         queryClient.invalidateQueries({ queryKey: ['agents'] })
-        // Einzelnen Agent-Cache aktualisieren
         queryClient.invalidateQueries({ queryKey: ['agent', agentId] })
       })
 
-      connection.on('AlertTriggered', (_agentId: string, agentHostname: string, ruleName: string, _message: string, _severity: string) => {
-        console.debug('[SignalR] AlertTriggered', agentHostname, ruleName)
-        // Alerts-Liste invalidieren
+      connection.on('AlertTriggered', () => {
         queryClient.invalidateQueries({ queryKey: ['alerts'] })
       })
     },
@@ -35,36 +27,47 @@ export function useGlobalSignalR() {
 }
 
 /**
- * Tritt der Agent-spezifischen Gruppe bei und hört auf Metriken + Command-Results.
- * Wird in AgentDetailPage verwendet.
+ * Tritt der Agent-Gruppe bei und empfängt Live-Metriken via SignalR.
+ * onLiveMetrics wird mit den aktuellen Metriken aufgerufen (direkt, ohne API-Roundtrip).
  */
-export function useAgentSignalR(agentId: string) {
+export function useAgentSignalR(
+  agentId: string,
+  onLiveMetrics?: (metrics: SystemMetrics) => void,
+) {
   const queryClient = useQueryClient()
   const connectionRef = useRef<signalR.HubConnection | null>(null)
+  const onLiveMetricsRef = useRef(onLiveMetrics)
+
+  // Ref aktuell halten ohne Re-Subscribe zu triggern
+  useEffect(() => {
+    onLiveMetricsRef.current = onLiveMetrics
+  }, [onLiveMetrics])
+
+  const handleMetrics = useCallback((id: string, metrics: SystemMetrics) => {
+    if (id !== agentId) return
+    // Live-Callback aufrufen (kein API-Call nötig)
+    onLiveMetricsRef.current?.(metrics)
+    // Query-Cache auch invalidieren damit historische Daten aktuell bleiben
+    queryClient.invalidateQueries({ queryKey: ['agentMetrics', agentId] })
+  }, [agentId, queryClient])
 
   const { status } = useSignalR({
     url: HUB_URL,
     onConnected: async (connection) => {
       connectionRef.current = connection
 
-      // Gruppe beitreten
       try {
         await connection.invoke('JoinAgentGroup', agentId)
       } catch (err) {
         console.warn('[SignalR] JoinAgentGroup failed:', err)
       }
 
-      connection.on('AgentMetricsUpdated', (id: string) => {
-        if (id === agentId) {
-          // Metriken neu laden
-          queryClient.invalidateQueries({ queryKey: ['agentMetrics', agentId] })
-        }
-      })
+      connection.on('AgentMetricsUpdated', handleMetrics)
 
       connection.on('CommandResultUpdated', (_taskId: string, id: string) => {
         if (id === agentId) {
-          // Tasks neu laden
           queryClient.invalidateQueries({ queryKey: ['agentTasks', agentId] })
+          queryClient.invalidateQueries({ queryKey: ['agent', agentId] })
         }
       })
     },
@@ -73,7 +76,6 @@ export function useAgentSignalR(agentId: string) {
     },
   })
 
-  // Gruppe verlassen wenn Komponente unmountet
   useEffect(() => {
     return () => {
       connectionRef.current?.invoke('LeaveAgentGroup', agentId).catch(() => {})

Frontend/src/index.css

@@ -33,4 +33,9 @@
     background-color: hsl(var(--background));
     color: hsl(var(--foreground));
   }
+  /* Dropdown-Optionen im Dark Mode sichtbar machen */
+  select option {
+    background-color: hsl(var(--card));
+    color: hsl(var(--foreground));
+  }
 }

Frontend/src/pages/SoftwarePage.tsx

@@ -15,13 +15,11 @@ export default function SoftwarePage() {
 
   const queryClient = useQueryClient()
 
-  // Fetch packages
   const { data: packages = [], isLoading } = useQuery({
     queryKey: ['software-packages', filterOs],
     queryFn: () => softwarePackagesApi.list(filterOs === 'All' ? undefined : filterOs),
   })
 
-  // Mutations
   const createMutation = useMutation({
     mutationFn: (data: CreateSoftwarePackageRequest) => softwarePackagesApi.create(data),
     onSuccess: () => {
@@ -96,134 +94,134 @@ export default function SoftwarePage() {
   }
 
   return (
-    <div className="min-h-screen bg-gray-50 p-8">
-      <div className="max-w-7xl mx-auto">
-        {/* Header */}
-        <div className="mb-8">
-          <div className="flex items-center gap-3 mb-2">
-            <Package className="text-blue-600" size={28} />
-            <h1 className="text-3xl font-bold">Software-Verwaltung</h1>
-          </div>
-          <p className="text-gray-600">Verwalte Software-Pakete und deploye sie auf Agenten</p>
+    <div className="p-6 space-y-6">
+      {/* Header */}
+      <div>
+        <div className="flex items-center gap-3 mb-1">
+          <Package className="text-primary" size={24} />
+          <h1 className="text-3xl font-bold text-foreground">Software-Verwaltung</h1>
         </div>
+        <p className="text-muted-foreground">Verwalte Software-Pakete und deploye sie auf Agenten</p>
+      </div>
 
-        {/* Tabs */}
-        <div className="flex gap-4 mb-6 border-b">
-          <button
-            onClick={() => setActiveTab('catalog')}
-            className={cn(
-              'px-4 py-2 font-medium text-sm border-b-2 transition-colors',
-              activeTab === 'catalog'
-                ? 'border-blue-600 text-blue-600'
-                : 'border-transparent text-gray-600 hover:text-gray-900'
-            )}
-          >
-            Katalog
-          </button>
-          <button
-            onClick={() => setActiveTab('deploy')}
-            className={cn(
-              'px-4 py-2 font-medium text-sm border-b-2 transition-colors',
-              activeTab === 'deploy'
-                ? 'border-blue-600 text-blue-600'
-                : 'border-transparent text-gray-600 hover:text-gray-900'
-            )}
-          >
-            Deployen
-          </button>
+      {/* Tabs */}
+      <div className="flex gap-2 border-b border-border">
+        <button
+          onClick={() => setActiveTab('catalog')}
+          className={cn(
+            'px-4 py-2 font-medium text-sm border-b-2 transition-colors',
+            activeTab === 'catalog'
+              ? 'border-primary text-primary'
+              : 'border-transparent text-muted-foreground hover:text-foreground'
+          )}
+        >
+          Katalog
+        </button>
+        <button
+          onClick={() => setActiveTab('deploy')}
+          className={cn(
+            'px-4 py-2 font-medium text-sm border-b-2 transition-colors',
+            activeTab === 'deploy'
+              ? 'border-primary text-primary'
+              : 'border-transparent text-muted-foreground hover:text-foreground'
+          )}
+        >
+          Deployen
+        </button>
+      </div>
+
+      {/* Messages */}
+      {successMessage && (
+        <div className="p-3 bg-green-500/20 text-green-400 border border-green-500/30 rounded-lg">
+          {successMessage}
         </div>
+      )}
+      {errorMessage && (
+        <div className="p-3 bg-red-500/20 text-red-400 border border-red-500/30 rounded-lg">
+          {errorMessage}
+        </div>
+      )}
 
-        {/* Messages */}
-        {successMessage && (
-          <div className="mb-4 p-3 bg-green-100 text-green-800 rounded-lg">{successMessage}</div>
-        )}
-        {errorMessage && (
-          <div className="mb-4 p-3 bg-red-100 text-red-800 rounded-lg">{errorMessage}</div>
-        )}
-
-        {/* Tab Content */}
-        {activeTab === 'catalog' && (
-          <div>
-            {/* Filter and Create Button */}
-            <div className="flex items-center justify-between mb-6">
-              <div className="flex gap-2">
-                {(['All', 'Windows', 'Linux'] as const).map((os) => (
-                  <button
-                    key={os}
-                    onClick={() => setFilterOs(os)}
-                    className={cn(
-                      'px-4 py-2 rounded-lg font-medium transition-colors',
-                      filterOs === os
-                        ? 'bg-blue-600 text-white'
-                        : 'bg-white text-gray-700 border border-gray-300 hover:bg-gray-50'
-                    )}
-                  >
-                    {os}
-                  </button>
-                ))}
-              </div>
-              <button
-                onClick={handleOpenCreate}
-                className="flex items-center gap-2 px-4 py-2 bg-blue-600 text-white rounded-lg hover:bg-blue-700 transition-colors"
-              >
-                <Plus size={18} />
-                Neues Paket
-              </button>
+      {/* Catalog Tab */}
+      {activeTab === 'catalog' && (
+        <div className="space-y-4">
+          <div className="flex items-center justify-between">
+            <div className="flex gap-2">
+              {(['All', 'Windows', 'Linux'] as const).map((os) => (
+                <button
+                  key={os}
+                  onClick={() => setFilterOs(os)}
+                  className={cn(
+                    'px-4 py-2 rounded-lg font-medium text-sm transition-colors',
+                    filterOs === os
+                      ? 'bg-primary text-primary-foreground'
+                      : 'bg-muted text-muted-foreground hover:text-foreground hover:bg-muted/80'
+                  )}
+                >
+                  {os}
+                </button>
+              ))}
             </div>
+            <button
+              onClick={handleOpenCreate}
+              className="flex items-center gap-2 px-4 py-2 bg-primary text-primary-foreground rounded-lg hover:bg-primary/90 transition-colors text-sm font-medium"
+            >
+              <Plus size={18} />
+              Neues Paket
+            </button>
+          </div>
 
-            {/* Table */}
-            {isLoading ? (
-              <div className="text-center py-8 text-gray-500">Laden...</div>
-            ) : packages.length === 0 ? (
-              <div className="text-center py-8 text-gray-500">
-                Keine Pakete {filterOs !== 'All' && `für ${filterOs}`} vorhanden
-              </div>
-            ) : (
-              <div className="bg-white rounded-lg shadow overflow-x-auto">
-                <table className="w-full">
-                  <thead className="bg-gray-100 border-b">
+          {isLoading ? (
+            <div className="text-center py-8 text-muted-foreground">Laden...</div>
+          ) : packages.length === 0 ? (
+            <div className="text-center py-8 text-muted-foreground">
+              Keine Pakete {filterOs !== 'All' && `für ${filterOs}`} vorhanden
+            </div>
+          ) : (
+            <div className="bg-card border border-border rounded-lg overflow-hidden">
+              <div className="overflow-x-auto">
+                <table className="w-full text-sm">
+                  <thead className="bg-muted border-b border-border">
                     <tr>
-                      <th className="px-6 py-3 text-left text-sm font-semibold text-gray-900">Name</th>
-                      <th className="px-6 py-3 text-left text-sm font-semibold text-gray-900">Version</th>
-                      <th className="px-6 py-3 text-left text-sm font-semibold text-gray-900">OS</th>
-                      <th className="px-6 py-3 text-left text-sm font-semibold text-gray-900">
-                        Paketmanager
-                      </th>
-                      <th className="px-6 py-3 text-left text-sm font-semibold text-gray-900">Paketname</th>
-                      <th className="px-6 py-3 text-right text-sm font-semibold text-gray-900">Aktionen</th>
+                      <th className="px-6 py-3 text-left font-semibold text-foreground">Name</th>
+                      <th className="px-6 py-3 text-left font-semibold text-foreground">Version</th>
+                      <th className="px-6 py-3 text-left font-semibold text-foreground">OS</th>
+                      <th className="px-6 py-3 text-left font-semibold text-foreground">Paketmanager</th>
+                      <th className="px-6 py-3 text-left font-semibold text-foreground">Paketname</th>
+                      <th className="px-6 py-3 text-right font-semibold text-foreground">Aktionen</th>
                     </tr>
                   </thead>
-                  <tbody>
+                  <tbody className="divide-y divide-border">
                     {packages.map((pkg) => (
-                      <tr key={pkg.id} className="border-b hover:bg-gray-50 transition-colors">
-                        <td className="px-6 py-4 font-medium text-gray-900">{pkg.name}</td>
-                        <td className="px-6 py-4 text-gray-600">{pkg.version}</td>
+                      <tr key={pkg.id} className="hover:bg-muted/50 transition-colors">
+                        <td className="px-6 py-4 font-medium text-foreground">{pkg.name}</td>
+                        <td className="px-6 py-4 text-muted-foreground">{pkg.version}</td>
                         <td className="px-6 py-4">
                           <span
                             className={cn(
-                              'px-3 py-1 rounded-full text-sm font-medium text-white',
+                              'px-3 py-1 rounded-full text-xs font-medium text-primary-foreground',
                               pkg.osType === 'Windows' ? 'bg-blue-600' : 'bg-green-600'
                             )}
                           >
                             {pkg.osType}
                           </span>
                         </td>
-                        <td className="px-6 py-4 text-gray-600">{pkg.packageManager}</td>
-                        <td className="px-6 py-4 text-gray-600 font-mono text-sm">{pkg.packageName}</td>
-                        <td className="px-6 py-4 flex justify-end gap-3">
+                        <td className="px-6 py-4 text-muted-foreground">{pkg.packageManager}</td>
+                        <td className="px-6 py-4 text-muted-foreground font-mono text-xs">{pkg.packageName}</td>
+                        <td className="px-6 py-4 flex justify-end gap-2">
                           <button
                             onClick={() => handleEdit(pkg)}
-                            className="p-2 text-blue-600 hover:bg-blue-50 rounded transition-colors"
+                            className="p-2 text-primary hover:bg-primary/10 rounded transition-colors"
                             title="Bearbeiten"
                           >
-                            <Edit size={18} />
+                            <Edit size={16} />
                           </button>
                           <button
                             onClick={() => handleDelete(pkg.id, pkg.name)}
-                            className="p-2 text-red-600 hover:bg-red-50 rounded transition-colors"
+                            className="p-2 text-red-400 hover:bg-red-500/10 rounded transition-colors"
                             title="Löschen"
                           >
-                            <Trash2 size={18} />
+                            <Trash2 size={16} />
                           </button>
                         </td>
                       </tr>
@@ -231,12 +229,12 @@ export default function SoftwarePage() {
                   </tbody>
                 </table>
               </div>
-            )}
-          </div>
-        )}
+            </div>
+          )}
+        </div>
+      )}
 
-        {activeTab === 'deploy' && <DeployTab packages={packages} deployMutation={deployMutation} />}
-      </div>
+      {activeTab === 'deploy' && <DeployTab packages={packages} deployMutation={deployMutation} />}
 
       {/* Create/Edit Modal */}
       {isCreateModalOpen && (
@@ -316,76 +314,72 @@ function CreatePackageModal({
       availableManagers.includes(formData.packageManager as PackageManager)
         ? (formData.packageManager as PackageManager)
         : (availableManagers[0] as PackageManager)
-
-    setFormData((prev) => ({
-      ...prev,
-      osType: newOs,
-      packageManager: newManager,
-    }))
+    setFormData((prev) => ({ ...prev, osType: newOs, packageManager: newManager }))
   }
 
+  const inputClass =
+    'w-full px-3 py-2 bg-background border border-border rounded-lg text-foreground text-sm focus:outline-none focus:ring-2 focus:ring-primary'
+
   if (!isOpen) return null
 
   return (
     <div className="fixed inset-0 bg-black/50 flex items-center justify-center z-50 p-4">
-      <div className="bg-white rounded-lg shadow-lg max-w-md w-full max-h-[90vh] overflow-y-auto">
-        <div className="flex items-center justify-between p-6 border-b sticky top-0 bg-white">
-          <h2 className="text-xl font-bold">
+      <div className="bg-card border border-border rounded-lg shadow-lg max-w-md w-full max-h-[90vh] overflow-y-auto">
+        <div className="flex items-center justify-between p-6 border-b border-border sticky top-0 bg-card">
+          <h2 className="text-xl font-bold text-foreground">
             {editingPackage ? 'Paket bearbeiten' : 'Neues Paket'}
           </h2>
-          <button onClick={onClose} className="text-gray-500 hover:text-gray-700">
-            <X size={24} />
+          <button onClick={onClose} className="text-muted-foreground hover:text-foreground">
+            <X size={20} />
           </button>
         </div>
 
         <form onSubmit={handleSubmit} className="p-6 space-y-4">
-          {/* Name */}
           <div>
-            <label className="block text-sm font-medium text-gray-900 mb-1">Name *</label>
+            <label className="block text-sm font-medium text-foreground mb-1">Name *</label>
             <input
               type="text"
               required
               value={formData.name}
               onChange={(e) => setFormData({ ...formData, name: e.target.value })}
-              className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500"
+              className={inputClass}
             />
           </div>
 
-          {/* Version */}
           <div>
-            <label className="block text-sm font-medium text-gray-900 mb-1">Version *</label>
+            <label className="block text-sm font-medium text-foreground mb-1">Version *</label>
             <input
               type="text"
               required
               placeholder="z.B. 1.0.0"
               value={formData.version}
               onChange={(e) => setFormData({ ...formData, version: e.target.value })}
-              className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500"
+              className={inputClass}
             />
           </div>
 
-          {/* OS */}
           <div>
-            <label className="block text-sm font-medium text-gray-900 mb-1">Betriebssystem *</label>
+            <label className="block text-sm font-medium text-foreground mb-1">Betriebssystem *</label>
             <select
               required
               value={formData.osType}
               onChange={(e) => handleOsChange(e.target.value as OsType)}
-              className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500"
+              className={inputClass}
             >
               <option value="Windows">Windows</option>
               <option value="Linux">Linux</option>
             </select>
           </div>
 
-          {/* Package Manager */}
           <div>
-            <label className="block text-sm font-medium text-gray-900 mb-1">Paketmanager *</label>
+            <label className="block text-sm font-medium text-foreground mb-1">Paketmanager *</label>
             <select
               required
               value={formData.packageManager}
-              onChange={(e) => setFormData({ ...formData, packageManager: e.target.value as PackageManager })}
-              className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500"
+              onChange={(e) =>
+                setFormData({ ...formData, packageManager: e.target.value as PackageManager })
+              }
+              className={inputClass}
             >
               {getAvailablePackageManagers().map((pm) => (
                 <option key={pm} value={pm}>
@@ -395,74 +389,71 @@ function CreatePackageModal({
             </select>
           </div>
 
-          {/* Package Name */}
           <div>
-            <label className="block text-sm font-medium text-gray-900 mb-1">Paketname *</label>
+            <label className="block text-sm font-medium text-foreground mb-1">Paketname *</label>
             <input
               type="text"
               required
               placeholder="Name wie im Paketmanager"
               value={formData.packageName}
               onChange={(e) => setFormData({ ...formData, packageName: e.target.value })}
-              className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500"
+              className={inputClass}
             />
           </div>
 
-          {/* Installer URL (nur für "direct") */}
           {formData.packageManager === 'direct' && (
-            <div>
-              <label className="block text-sm font-medium text-gray-900 mb-1">Installer URL</label>
-              <input
-                type="url"
-                placeholder="https://..."
-                value={formData.installerUrl || ''}
-                onChange={(e) => setFormData({ ...formData, installerUrl: e.target.value || undefined })}
-                className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500"
-              />
-            </div>
+            <>
+              <div>
+                <label className="block text-sm font-medium text-foreground mb-1">Installer URL</label>
+                <input
+                  type="url"
+                  placeholder="https://..."
+                  value={formData.installerUrl || ''}
+                  onChange={(e) =>
+                    setFormData({ ...formData, installerUrl: e.target.value || undefined })
+                  }
+                  className={inputClass}
+                />
+              </div>
+              <div>
+                <label className="block text-sm font-medium text-foreground mb-1">SHA256-Prüfsumme</label>
+                <input
+                  type="text"
+                  placeholder="SHA256 hash"
+                  value={formData.checksum || ''}
+                  onChange={(e) =>
+                    setFormData({ ...formData, checksum: e.target.value || undefined })
+                  }
+                  className={cn(inputClass, 'font-mono text-xs')}
+                />
+              </div>
+              <div>
+                <label className="block text-sm font-medium text-foreground mb-1">Silent-Argumente</label>
+                <input
+                  type="text"
+                  placeholder="/S, --silent, etc."
+                  value={formData.silentArgs || ''}
+                  onChange={(e) =>
+                    setFormData({ ...formData, silentArgs: e.target.value || undefined })
+                  }
+                  className={inputClass}
+                />
+              </div>
+            </>
           )}
 
-          {/* Checksum (nur für "direct") */}
-          {formData.packageManager === 'direct' && (
-            <div>
-              <label className="block text-sm font-medium text-gray-900 mb-1">SHA256-Prüfsumme</label>
-              <input
-                type="text"
-                placeholder="SHA256 hash"
-                value={formData.checksum || ''}
-                onChange={(e) => setFormData({ ...formData, checksum: e.target.value || undefined })}
-                className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500 font-mono text-xs"
-              />
-            </div>
-          )}
-
-          {/* Silent Args (nur für "direct") */}
-          {formData.packageManager === 'direct' && (
-            <div>
-              <label className="block text-sm font-medium text-gray-900 mb-1">Silent-Argumente</label>
-              <input
-                type="text"
-                placeholder="/S, --silent, etc."
-                value={formData.silentArgs || ''}
-                onChange={(e) => setFormData({ ...formData, silentArgs: e.target.value || undefined })}
-                className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500"
-              />
-            </div>
-          )}
-
-          {/* Buttons */}
           <div className="flex gap-3 pt-4">
             <button
               type="button"
               onClick={onClose}
-              className="flex-1 px-4 py-2 border border-gray-300 rounded-lg text-gray-700 hover:bg-gray-50 transition-colors font-medium"
+              className="flex-1 px-4 py-2 border border-border rounded-lg text-muted-foreground hover:text-foreground hover:bg-accent transition-colors font-medium text-sm"
             >
               Abbrechen
             </button>
             <button
               type="submit"
               disabled={isLoading}
-              className="flex-1 px-4 py-2 bg-blue-600 text-white rounded-lg hover:bg-blue-700 transition-colors font-medium disabled:opacity-50"
+              className="flex-1 px-4 py-2 bg-primary text-primary-foreground rounded-lg hover:bg-primary/90 transition-colors font-medium text-sm disabled:opacity-50"
             >
               {isLoading ? 'Speichern...' : editingPackage ? 'Aktualisieren' : 'Erstellen'}
             </button>
@@ -475,7 +466,7 @@ function CreatePackageModal({
 
 interface DeployTabProps {
   packages: SoftwarePackage[]
-  deployMutation: any
+  deployMutation: ReturnType<typeof useMutation<unknown, Error, { agentId: string; packageId: number; action: 'install' | 'uninstall' }>>
 }
 
 function DeployTab({ packages, deployMutation }: DeployTabProps) {
@@ -483,28 +474,26 @@ function DeployTab({ packages, deployMutation }: DeployTabProps) {
   const [agentId, setAgentId] = useState('')
   const [action, setAction] = useState<'install' | 'uninstall'>('install')
 
+  const inputClass =
+    'w-full px-3 py-2 bg-background border border-border rounded-lg text-foreground text-sm focus:outline-none focus:ring-2 focus:ring-primary'
+
   const handleDeploy = (e: React.FormEvent) => {
     e.preventDefault()
     if (!selectedPackageId || !agentId) return
-    deployMutation.mutate({
-      agentId,
-      packageId: selectedPackageId as number,
-      action,
-    })
+    deployMutation.mutate({ agentId, packageId: selectedPackageId as number, action })
   }
 
   return (
     <div className="max-w-lg">
-      <div className="bg-white rounded-lg shadow p-6">
+      <div className="bg-card border border-border rounded-lg p-6">
         <form onSubmit={handleDeploy} className="space-y-4">
-          {/* Package Selection */}
           <div>
-            <label className="block text-sm font-medium text-gray-900 mb-2">Paket auswählen *</label>
+            <label className="block text-sm font-medium text-foreground mb-2">Paket auswählen *</label>
             <select
               required
               value={selectedPackageId}
               onChange={(e) => setSelectedPackageId(e.target.value ? Number(e.target.value) : '')}
-              className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500"
+              className={inputClass}
             >
               <option value="">-- Paket auswählen --</option>
               {packages.map((pkg) => (
@@ -515,65 +504,54 @@ function DeployTab({ packages, deployMutation }: DeployTabProps) {
             </select>
           </div>
 
-          {/* Agent ID */}
           <div>
-            <label className="block text-sm font-medium text-gray-900 mb-2">Agent-ID *</label>
+            <label className="block text-sm font-medium text-foreground mb-2">Agent-ID *</label>
             <input
               type="text"
               required
               placeholder="UUID des Agenten (aus Dashboard kopieren)"
               value={agentId}
               onChange={(e) => setAgentId(e.target.value)}
-              className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500 font-mono text-sm"
+              className={cn(inputClass, 'font-mono')}
             />
-            <p className="mt-1 text-xs text-gray-500">
+            <p className="mt-1 text-xs text-muted-foreground">
               Finde die Agent-ID im Agent-Dashboard oder Agent-Details
             </p>
           </div>
 
-          {/* Action */}
           <div>
-            <label className="block text-sm font-medium text-gray-900 mb-2">Aktion *</label>
+            <label className="block text-sm font-medium text-foreground mb-2">Aktion *</label>
             <div className="space-y-2">
-              <label className="flex items-center gap-3 cursor-pointer">
-                <input
-                  type="radio"
-                  name="action"
-                  value="install"
-                  checked={action === 'install'}
-                  onChange={() => setAction('install')}
-                  className="w-4 h-4"
-                />
-                <span className="text-gray-900">Installieren</span>
-              </label>
-              <label className="flex items-center gap-3 cursor-pointer">
-                <input
-                  type="radio"
-                  name="action"
-                  value="uninstall"
-                  checked={action === 'uninstall'}
-                  onChange={() => setAction('uninstall')}
-                  className="w-4 h-4"
-                />
-                <span className="text-gray-900">Deinstallieren</span>
-              </label>
+              {(['install', 'uninstall'] as const).map((a) => (
+                <label key={a} className="flex items-center gap-3 cursor-pointer">
+                  <input
+                    type="radio"
+                    name="action"
+                    value={a}
+                    checked={action === a}
+                    onChange={() => setAction(a)}
+                    className="w-4 h-4 accent-primary"
+                  />
+                  <span className="text-foreground text-sm">
+                    {a === 'install' ? 'Installieren' : 'Deinstallieren'}
+                  </span>
+                </label>
+              ))}
             </div>
           </div>
 
-          {/* Submit */}
           <button
             type="submit"
             disabled={deployMutation.isPending || !selectedPackageId || !agentId}
-            className="w-full flex items-center justify-center gap-2 px-4 py-2 bg-blue-600 text-white rounded-lg hover:bg-blue-700 transition-colors font-medium disabled:opacity-50 disabled:cursor-not-allowed"
+            className="w-full flex items-center justify-center gap-2 px-4 py-2 bg-primary text-primary-foreground rounded-lg hover:bg-primary/90 transition-colors font-medium text-sm disabled:opacity-50 disabled:cursor-not-allowed"
           >
             <Rocket size={18} />
             {deployMutation.isPending ? 'Wird deployed...' : 'Deploy starten'}
           </button>
 
-          {/* Info */}
-          <div className="mt-4 p-3 bg-blue-50 border border-blue-200 rounded-lg text-sm text-blue-900">
+          <div className="p-3 bg-primary/10 border border-primary/20 rounded-lg text-sm text-foreground">
             <p className="font-medium mb-1">Hinweis:</p>
-            <p>
+            <p className="text-muted-foreground">
               Die Task wird erstellt und der Agent führt sie beim nächsten Heartbeat aus (ca. 1-2 Minuten).
               Überwache den Task-Fortschritt im Agent-Dashboard.
             </p>

dev-start.ps1

@@ -3,55 +3,50 @@
 .SYNOPSIS
     Startet die NexusRMM Entwicklungsumgebung
 .DESCRIPTION
-    Startet Docker (Postgres + MeshCentral), führt DB-Migrationen aus,
+    Startet Docker (Postgres), fuehrt DB-Migrationen aus,
     startet Backend und Frontend in separaten Fenstern.
 #>
 
-$ErrorActionPreference = "Stop"
+$ErrorActionPreference = "Continue"
 $Root = "D:\001_Projekte\IT_Tool"
 
-# ---------------------------------------------------------------------------
-# Helper-Funktionen
-# ---------------------------------------------------------------------------
-function Write-Step { param($msg) Write-Host "`n==> $msg" -ForegroundColor Cyan }
+function Write-Step { param($msg) Write-Host "" ; Write-Host "==> $msg" -ForegroundColor Cyan }
 function Write-OK   { param($msg) Write-Host "    [OK] $msg"     -ForegroundColor Green }
 function Write-Warn { param($msg) Write-Host "    [!]  $msg"     -ForegroundColor Yellow }
 function Write-Fail { param($msg) Write-Host "    [FEHLER] $msg" -ForegroundColor Red }
 
 # ---------------------------------------------------------------------------
-# 1. Voraussetzungen prüfen
+# 1. Voraussetzungen pruefen
 # ---------------------------------------------------------------------------
-Write-Step "Prüfe Voraussetzungen..."
+Write-Step "Pruefe Voraussetzungen..."
 
 $missing = $false
-
 $tools = @(
     @{ Name = "docker";  Desc = "Docker Desktop" },
     @{ Name = "dotnet";  Desc = ".NET SDK" },
     @{ Name = "node";    Desc = "Node.js" },
-    @{ Name = "npm";     Desc = "npm" },
-    @{ Name = "go";      Desc = "Go" }
+    @{ Name = "npm";     Desc = "npm" }
 )
 
 foreach ($tool in $tools) {
     $cmd = Get-Command $tool.Name -ErrorAction SilentlyContinue
     if ($null -eq $cmd) {
-        Write-Fail "$($tool.Desc) ($($tool.Name)) nicht gefunden. Bitte installieren."
+        Write-Fail "$($tool.Desc) ($($tool.Name)) nicht gefunden."
         $missing = $true
     } else {
-        Write-OK "$($tool.Desc): $($cmd.Source)"
+        Write-OK "$($tool.Desc): gefunden"
     }
 }
 
 if ($missing) {
-    Write-Fail "Fehlende Voraussetzungen – Abbruch."
+    Write-Fail "Fehlende Voraussetzungen. Bitte installieren und erneut starten."
     exit 1
 }
 
-# dotnet-ef prüfen
-$efInstalled = dotnet tool list --global 2>$null | Select-String "dotnet-ef"
-if (-not $efInstalled) {
-    Write-Warn "dotnet-ef nicht global installiert. Installiere jetzt..."
+# dotnet-ef pruefen
+$efCheck = dotnet tool list --global 2>$null | Select-String "dotnet-ef"
+if (-not $efCheck) {
+    Write-Warn "dotnet-ef nicht gefunden. Installiere..."
     dotnet tool install --global dotnet-ef
     if ($LASTEXITCODE -ne 0) {
         Write-Fail "dotnet-ef konnte nicht installiert werden."
@@ -67,25 +62,20 @@ if (-not $efInstalled) {
 # ---------------------------------------------------------------------------
 Write-Step "Starte PostgreSQL..."
 
-Push-Location $Root
-try {
-    docker compose up -d nexusrmm-postgres
-    if ($LASTEXITCODE -ne 0) {
-        Write-Fail "docker compose up fehlgeschlagen."
-        exit 1
-    }
-} finally {
-    Pop-Location
+Set-Location $Root
+docker compose up -d nexusrmm-postgres
+if ($LASTEXITCODE -ne 0) {
+    Write-Fail "docker compose up fehlgeschlagen. Laeuft Docker Desktop?"
+    exit 1
 }
 
-# Warte bis PostgreSQL bereit ist (max 30 Sekunden, Intervall 2 Sekunden)
 Write-Host "    Warte auf PostgreSQL..." -ForegroundColor Cyan
-$maxWait   = 30
-$waited    = 0
-$pgReady   = $false
+$maxWait = 30
+$waited  = 0
+$pgReady = $false
 
 while ($waited -lt $maxWait) {
-    $result = docker exec nexusrmm-postgres pg_isready -U nexusrmm -q 2>&1
+    docker exec nexusrmm-postgres pg_isready -U nexusrmm -q 2>$null
     if ($LASTEXITCODE -eq 0) {
         $pgReady = $true
         break
@@ -101,37 +91,30 @@ if (-not $pgReady) {
 Write-OK "PostgreSQL bereit (Port 5433)."
 
 # ---------------------------------------------------------------------------
-# 3. EF Core Migrationen ausführen
+# 3. EF Core Migrationen
 # ---------------------------------------------------------------------------
-Write-Step "Führe Datenbank-Migrationen aus..."
+Write-Step "Fuehre Datenbank-Migrationen aus..."
 
-Push-Location "$Root\Backend"
-try {
-    # --project: Migration-Projekt (Infrastructure enthält DbContext + Migrations)
-    # --startup-project: Startup-Projekt mit Verbindungsstring
-    dotnet ef database update `
-        --project  "src\NexusRMM.Infrastructure" `
-        --startup-project "src\NexusRMM.Api" `
-        --no-build
+Set-Location "$Root\Backend"
+
+dotnet ef database update --project "src\NexusRMM.Infrastructure" --startup-project "src\NexusRMM.Api" --no-build 2>&1 | Out-Default
+if ($LASTEXITCODE -ne 0) {
+    Write-Warn "Migration mit --no-build fehlgeschlagen. Baue zuerst..."
+    dotnet build "src\NexusRMM.Api" --configuration Debug -q
     if ($LASTEXITCODE -ne 0) {
-        # --no-build schlägt fehl wenn noch kein Build vorhanden – Build nachholen
-        Write-Warn "Migration mit --no-build fehlgeschlagen, baue zuerst..."
-        dotnet build "src\NexusRMM.Api" --configuration Debug -q
-        if ($LASTEXITCODE -ne 0) {
-            Write-Fail "dotnet build fehlgeschlagen."
-            exit 1
-        }
-        dotnet ef database update `
-            --project  "src\NexusRMM.Infrastructure" `
-            --startup-project "src\NexusRMM.Api"
-        if ($LASTEXITCODE -ne 0) {
-            Write-Fail "dotnet ef database update fehlgeschlagen."
-            exit 1
-        }
+        Write-Fail "dotnet build fehlgeschlagen."
+        Set-Location $Root
+        exit 1
+    }
+    dotnet ef database update --project "src\NexusRMM.Infrastructure" --startup-project "src\NexusRMM.Api"
+    if ($LASTEXITCODE -ne 0) {
+        Write-Fail "dotnet ef database update fehlgeschlagen."
+        Set-Location $Root
+        exit 1
     }
-} finally {
-    Pop-Location
 }
+
+Set-Location $Root
 Write-OK "Migrationen erfolgreich."
 
 # ---------------------------------------------------------------------------
@@ -139,20 +122,14 @@ Write-OK "Migrationen erfolgreich."
 # ---------------------------------------------------------------------------
 Write-Step "Starte Backend..."
 
-$backendCmd = "Set-Location '$Root\Backend'; Write-Host 'NexusRMM Backend' -ForegroundColor Cyan; dotnet run --project src/NexusRMM.Api"
-
-Start-Process powershell -ArgumentList @(
-    "-NoExit",
-    "-Command",
-    $backendCmd
-) -WindowStyle Normal
-
-Write-OK "Backend-Fenster geöffnet."
+$backendCmd = "Set-Location '$Root\Backend'; Write-Host 'NexusRMM Backend gestartet' -ForegroundColor Cyan; dotnet run --project src/NexusRMM.Api"
+Start-Process powershell -ArgumentList "-NoExit", "-Command", $backendCmd -WindowStyle Normal
+Write-OK "Backend-Fenster geoeffnet."
 
 # ---------------------------------------------------------------------------
-# 5. Kurz warten damit das Backend starten kann
+# 5. Kurz warten
 # ---------------------------------------------------------------------------
-Write-Host "`n    Warte 5 Sekunden damit das Backend hochfahren kann..." -ForegroundColor Cyan
+Write-Host "    Warte 5 Sekunden fuer Backend-Start..." -ForegroundColor Cyan
 Start-Sleep -Seconds 5
 
 # ---------------------------------------------------------------------------
@@ -160,29 +137,24 @@ Start-Sleep -Seconds 5
 # ---------------------------------------------------------------------------
 Write-Step "Starte Frontend..."
 
-$frontendCmd = "Set-Location '$Root\Frontend'; Write-Host 'NexusRMM Frontend' -ForegroundColor Cyan; npm run dev"
-
-Start-Process powershell -ArgumentList @(
-    "-NoExit",
-    "-Command",
-    $frontendCmd
-) -WindowStyle Normal
-
-Write-OK "Frontend-Fenster geöffnet."
+$frontendCmd = "Set-Location '$Root\Frontend'; Write-Host 'NexusRMM Frontend gestartet' -ForegroundColor Cyan; npm run dev"
+Start-Process powershell -ArgumentList "-NoExit", "-Command", $frontendCmd -WindowStyle Normal
+Write-OK "Frontend-Fenster geoeffnet."
 
 # ---------------------------------------------------------------------------
 # 7. Zusammenfassung
 # ---------------------------------------------------------------------------
 Write-Host ""
-Write-Host "╔══════════════════════════════════════════╗" -ForegroundColor Green
-Write-Host "║    NexusRMM ist bereit!                  ║" -ForegroundColor Green
-Write-Host "╠══════════════════════════════════════════╣" -ForegroundColor Green
-Write-Host "║  Frontend:    http://localhost:5173      ║" -ForegroundColor Green
-Write-Host "║  Backend:     http://localhost:5000      ║" -ForegroundColor Green
-Write-Host "║  Swagger:     http://localhost:5000/swagger ║" -ForegroundColor Green
-Write-Host "║  gRPC:        http://localhost:5001      ║" -ForegroundColor Green
-Write-Host "║  MeshCentral: https://localhost:4430     ║" -ForegroundColor Green
-Write-Host "╚══════════════════════════════════════════╝" -ForegroundColor Green
+Write-Host "+------------------------------------------+" -ForegroundColor Green
+Write-Host "|       NexusRMM ist bereit!               |" -ForegroundColor Green
+Write-Host "+------------------------------------------+" -ForegroundColor Green
+Write-Host "|  Frontend:    http://localhost:5173      |" -ForegroundColor Green
+Write-Host "|  Backend:     http://localhost:5000      |" -ForegroundColor Green
+Write-Host "|  Swagger:     http://localhost:5000/swagger |" -ForegroundColor Green
+Write-Host "|  gRPC:        http://localhost:5001      |" -ForegroundColor Green
+Write-Host "|  MeshCentral: https://localhost:4430     |" -ForegroundColor Green
+Write-Host "+------------------------------------------+" -ForegroundColor Green
 Write-Host ""
 Write-Host "Agent starten:  .\Agent\nexus-agent.exe" -ForegroundColor Yellow
 Write-Host "Alles stoppen:  .\dev-stop.ps1" -ForegroundColor Yellow
+Write-Host ""

install-service.ps1

@@ -0,0 +1,127 @@
+#Requires -RunAsAdministrator
+<#
+.SYNOPSIS
+    Installiert den NexusRMM Agent als Windows Service
+.DESCRIPTION
+    Baut den Agent, kopiert ihn ins Zielverzeichnis und registriert ihn als Windows Service.
+    Muss als Administrator ausgefuehrt werden.
+.PARAMETER ServerAddress
+    gRPC-Adresse des NexusRMM Servers (Standard: localhost:5001)
+.PARAMETER InstallDir
+    Installationsverzeichnis (Standard: C:\Program Files\NexusRMM)
+#>
+param(
+    [string]$ServerAddress = "localhost:5001",
+    [string]$InstallDir = "C:\Program Files\NexusRMM"
+)
+
+$ErrorActionPreference = "Continue"
+$Root = $PSScriptRoot
+
+function Write-Step { param($msg) Write-Host "" ; Write-Host "==> $msg" -ForegroundColor Cyan }
+function Write-OK   { param($msg) Write-Host "    [OK] $msg"     -ForegroundColor Green }
+function Write-Fail { param($msg) Write-Host "    [FEHLER] $msg" -ForegroundColor Red }
+
+# ---------------------------------------------------------------------------
+# 1. Agent bauen
+# ---------------------------------------------------------------------------
+Write-Step "Baue NexusRMM Agent..."
+
+Set-Location "$Root\Agent"
+$env:GOOS = "windows"
+$env:GOARCH = "amd64"
+go build -ldflags "-s -w -X main.version=1.0.0" -o nexus-agent.exe ./cmd/agent
+if ($LASTEXITCODE -ne 0) {
+    Write-Fail "go build fehlgeschlagen."
+    exit 1
+}
+Write-OK "nexus-agent.exe erstellt."
+
+# ---------------------------------------------------------------------------
+# 2. Installationsverzeichnis anlegen
+# ---------------------------------------------------------------------------
+Write-Step "Lege Installationsverzeichnis an: $InstallDir"
+
+if (-not (Test-Path $InstallDir)) {
+    New-Item -ItemType Directory -Path $InstallDir -Force | Out-Null
+}
+Write-OK "Verzeichnis bereit."
+
+# ---------------------------------------------------------------------------
+# 3. Dateien kopieren
+# ---------------------------------------------------------------------------
+Write-Step "Kopiere Dateien..."
+
+Copy-Item "$Root\Agent\nexus-agent.exe" "$InstallDir\nexus-agent.exe" -Force
+
+# Konfigurationsdatei anlegen falls nicht vorhanden
+$configPath = "$InstallDir\nexus-agent.yaml"
+if (-not (Test-Path $configPath)) {
+    @"
+serverAddress: $ServerAddress
+agentId: ""
+heartbeatInterval: 30
+meshEnabled: false
+meshCentralUrl: ""
+"@ | Out-File -FilePath $configPath -Encoding utf8
+    Write-OK "nexus-agent.yaml erstellt (serverAddress: $ServerAddress)."
+} else {
+    Write-OK "nexus-agent.yaml bereits vorhanden, wird nicht ueberschrieben."
+}
+
+# ---------------------------------------------------------------------------
+# 4. Bestehenden Service stoppen/deinstallieren falls vorhanden
+# ---------------------------------------------------------------------------
+$exePath = "$InstallDir\nexus-agent.exe"
+
+$svcCheck = Get-Service -Name "NexusRMMAgent" -ErrorAction SilentlyContinue
+if ($svcCheck) {
+    Write-Step "Entferne vorhandenen Service..."
+    & $exePath stop 2>$null
+    Start-Sleep -Seconds 2
+    & $exePath uninstall
+    if ($LASTEXITCODE -ne 0) {
+        Write-Fail "Service-Deinstallation fehlgeschlagen."
+        exit 1
+    }
+    Write-OK "Alter Service entfernt."
+}
+
+# ---------------------------------------------------------------------------
+# 5. Service installieren und starten
+# ---------------------------------------------------------------------------
+Write-Step "Installiere Service..."
+
+& $exePath install
+if ($LASTEXITCODE -ne 0) {
+    Write-Fail "Service-Installation fehlgeschlagen."
+    exit 1
+}
+Write-OK "Service installiert."
+
+Write-Step "Starte Service..."
+& $exePath start
+if ($LASTEXITCODE -ne 0) {
+    Write-Fail "Service konnte nicht gestartet werden."
+    exit 1
+}
+Write-OK "Service gestartet."
+
+# ---------------------------------------------------------------------------
+# Zusammenfassung
+# ---------------------------------------------------------------------------
+Write-Host ""
+Write-Host "+--------------------------------------------------+" -ForegroundColor Green
+Write-Host "|   NexusRMM Agent als Service installiert!       |" -ForegroundColor Green
+Write-Host "+--------------------------------------------------+" -ForegroundColor Green
+Write-Host "|  Installiert in: $InstallDir" -ForegroundColor Green
+Write-Host "|  Server:         $ServerAddress" -ForegroundColor Green
+Write-Host "|  Service-Name:   NexusRMMAgent" -ForegroundColor Green
+Write-Host "+--------------------------------------------------+" -ForegroundColor Green
+Write-Host ""
+Write-Host "Verwalten:" -ForegroundColor Yellow
+Write-Host "  Start:       & '$exePath' start" -ForegroundColor Yellow
+Write-Host "  Stop:        & '$exePath' stop" -ForegroundColor Yellow
+Write-Host "  Entfernen:   & '$exePath' uninstall" -ForegroundColor Yellow
+Write-Host "  Oder via:    services.msc -> NexusRMMAgent" -ForegroundColor Yellow
+Write-Host ""