feat: HA-Cluster v1.2.x — Split-Brain, TOTP, Enterprise-FW, Drift-Fix, VIP-Recovery

- keepalived: pg_role='standby' hat Vorrang vor role für BACKUP-Bestimmung
- keepalived-master.sh: gecrasht Dienste beim MASTER-Übergang starten (nicht nur reload)
- confighash: ip_addresses per Interface-Name hashen statt per FK (Cross-Node-Drift-Fix)
- TOTP/2FA: RFC 6238 — Setup-Flow, QR-Code, Admin-Disable; two-step Login
- Firewall-UI: Enterprise-Design — auto-Beschreibung, icon-only Actions, zero-hit Indikator
- fe80-Filter: Link-local IPv6 aus NTP/DNS Listen-Dropdowns entfernen
- VIP-Dashboard, Dual-Path VRRP, GW-Tracking (Migrations 0033/0034)
- Forward Proxy + DNS erweiterte Einstellungen (Migrations 0031/0032)
- unbound-control: edgeguard in unbound-Gruppe via postinst

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

internal/handlers/system.go

@@ -122,6 +122,7 @@ func (h *SystemHandler) Register(rg *gin.RouterGroup) {
 	g.GET("/ipv6", h.IPv6)
 	g.POST("/ipv6", h.SetIPv6)
 	g.GET("/config-preview", h.ConfigPreview)
+	g.GET("/vip-status", h.VIPStatus)
 }
 
 // RegisterAgent mountet die read-only System-Endpoints auf der mTLS-
@@ -188,6 +189,7 @@ var servicesToCheck = []struct{ Label, Unit string }{
 	{"edgeguard-scheduler", "edgeguard-scheduler"},
 	{"haproxy", "haproxy"},
 	{"nftables", "nftables"},
+	{"keepalived", "keepalived"},
 	{"unbound", "unbound"},
 	{"chrony", "chrony"},
 	{"squid", "squid"},
@@ -1077,6 +1079,87 @@ func classifyLinkType(ifc net.Interface) string {
 	return ""
 }
 
+// VIPStatus returns the VRRP state and active VIPs for this node.
+// Uses net.Interfaces() (no shell-out) to check which VIPs from
+// ip_addresses WHERE is_vip=true are currently assigned locally.
+// MASTER = at least one VIP is locally present; BACKUP = none present.
+func (h *SystemHandler) VIPStatus(c *gin.Context) {
+	type vipEntry struct {
+		Address string `json:"address"`
+		Prefix  int    `json:"prefix"`
+		Device  string `json:"device"`
+		Active  bool   `json:"active"`
+	}
+	type vipStatus struct {
+		VRRPState        string     `json:"vrrp_state"`
+		KeepalivedActive bool       `json:"keepalived_active"`
+		VIPs             []vipEntry `json:"vips"`
+	}
+
+	ctx := c.Request.Context()
+
+	// keepalived service active?
+	kaOut, _ := exec.CommandContext(ctx, "systemctl", "is-active", "keepalived").Output()
+	kaActive := strings.TrimSpace(string(kaOut)) == "active"
+
+	// query VIPs from DB
+	var dbVIPs []vipEntry
+	if h.Pool != nil {
+		rows, err := h.Pool.Query(ctx,
+			`SELECT a.address, a.prefix, COALESCE(i.name,'') AS device
+			   FROM ip_addresses a
+			   LEFT JOIN network_interfaces i ON i.id = a.interface_id
+			  WHERE a.is_vip = true AND a.active = true
+			  ORDER BY a.address`)
+		if err == nil {
+			defer rows.Close()
+			for rows.Next() {
+				var e vipEntry
+				if err2 := rows.Scan(&e.Address, &e.Prefix, &e.Device); err2 == nil {
+					dbVIPs = append(dbVIPs, e)
+				}
+			}
+		}
+	}
+
+	// build set of locally assigned IPs
+	localIPs := make(map[string]bool)
+	if ifaces, err := net.Interfaces(); err == nil {
+		for _, ifc := range ifaces {
+			if addrs, err2 := ifc.Addrs(); err2 == nil {
+				for _, a := range addrs {
+					if ipnet, ok := a.(*net.IPNet); ok {
+						localIPs[ipnet.IP.String()] = true
+					}
+				}
+			}
+		}
+	}
+
+	anyActive := false
+	for i := range dbVIPs {
+		dbVIPs[i].Active = localIPs[dbVIPs[i].Address]
+		if dbVIPs[i].Active {
+			anyActive = true
+		}
+	}
+
+	state := "UNKNOWN"
+	if kaActive {
+		if anyActive {
+			state = "MASTER"
+		} else {
+			state = "BACKUP"
+		}
+	}
+
+	response.OK(c, vipStatus{
+		VRRPState:        state,
+		KeepalivedActive: kaActive,
+		VIPs:             dbVIPs,
+	})
+}
+
 func flagsToList(f net.Flags) []string {
 	var out []string
 	if f&net.FlagUp != 0 {