feat(dhcp): DHCPv4-Server via Kea (kea-dhcp4-server) — v1.2.92

Verwalteter DHCPv4-Server analog Unbound/Squid/Chrony.
- Migration 0041: dhcp_settings (singleton, node-lokal), dhcp_subnets, dhcp_reservations.
- internal/kea: Renderer baut Kea-JSON via Go-Struct→Marshal (garantiert valide), managed /etc/edgeguard/kea/kea-dhcp4.conf (Symlink von /etc/kea), Service-Lifecycle an enabled gekoppelt (default AUS, kein rogue DHCP). Interface per NAME (cluster-sicher, kein node-lokaler FK).
- internal/services/dhcp + internal/handlers/dhcp.go: Settings + Subnet/Reservation-CRUD, Validierung (CIDR/IP/MAC/interface exists).
- configgen: Stop/Enable/DisableService. Firewall: AutoFWRule.Iface → udp/67 pro LAN-Interface gescopt (kein WAN). Cluster: subnets/reservations repliziert (hashSpec), dhcp_settings node-lokal (localOnlyTables).
- main.go + render.go + WithAllReloaders Wiring. Packaging: kea-dhcp4-server Dependency, /etc/edgeguard/kea Dir, Symlink, disable-on-install, sudoers (restart/stop/enable/disable).
- UI: DHCP-Seite (Settings + Subnets + Reservierungen pro Subnet), Route/Nav/i18n de/en, HA-Warnung 'nur auf einer Node aktivieren'.
- Tests (guarded EG_FWTEST_DSN): Kea-Renderer gegen DB (valides JSON + Felder), FW-Auto-Rule-Iface inkl. nft -c. Scope v1: DHCPv4.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

internal/firewall/firewall.go

@@ -150,6 +150,7 @@ type AutoFWRule struct {
 	Proto   string
 	Port    int
 	DstIP   string
+	Iface   string // optional: scope auf ein iifname (z.B. DHCP udp/67 nur auf LAN)
 	Comment string
 }
 
@@ -417,6 +418,22 @@ func (g *Generator) loadAutoRules(ctx context.Context) []AutoFWRule {
 		}
 	}
 
+	// DHCP (Kea): wenn auf DIESER Node aktiviert → udp/67 pro aktivem
+	// Subnet-Interface (gescopt auf die LAN-iface, NICHT global/WAN).
+	var dhcpEnabled bool
+	if err := g.Pool.QueryRow(ctx, `SELECT enabled FROM dhcp_settings WHERE id=1`).Scan(&dhcpEnabled); err == nil && dhcpEnabled {
+		rows, err := g.Pool.Query(ctx, `SELECT DISTINCT interface_name FROM dhcp_subnets WHERE active AND interface_name <> ''`)
+		if err == nil {
+			defer rows.Close()
+			for rows.Next() {
+				var iface string
+				if rows.Scan(&iface) == nil && iface != "" {
+					out = append(out, AutoFWRule{Proto: "udp", Port: 67, Iface: iface, Comment: "DHCP (Kea) auf " + iface})
+				}
+			}
+		}
+	}
+
 	return out
 }