feat(radius): RADIUS-Server via FreeRADIUS (PAP/CHAP) — v1.2.93

Files-basierter RADIUS-Server (Clients + Users), managed analog DHCP/WireGuard.
- Migration 0042: radius_settings (singleton, node-lokal), radius_clients (secret_enc), radius_users (password_enc) — Secrets via secrets.Box verschlüsselt.
- internal/freeradius: Multi-File-Renderer (clients.conf + authorize) via Box.Open, Secret-Escaping (" \), Service default-off/an enabled gekoppelt. internal/services/radius + internal/handlers/radius.go: Settings + Client/User-CRUD, write-only Secret-Semantik, Validierung (IP/CIDR, name-charset), GET liefert secret_configured statt Secret.
- Firewall: udp 1812/1813 Auto-Rule bei enabled. Cluster: clients/users repliziert (hashSpec), radius_settings node-lokal.
- main.go + render.go + WithAllReloaders. Packaging: freeradius Dependency, setgid-Dir /etc/edgeguard/freeradius (Gruppe freeradius), Symlinks clients.conf+authorize, disable-on-install, sudoers.
- UI: RADIUS-Seite (Einstellungen + Clients + Benutzer) unter Sicherheit, Route/Nav/i18n de/en.
- Tests (guarded): Renderer-Inhalt + Secret-Escaping/Roundtrip + Masking. Scope v1: PAP/CHAP files-based (kein EAP/802.1X).

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

packaging/debian/edgeguard-api/DEBIAN/postinst

@@ -31,6 +31,11 @@ case "$1" in
         if getent group unbound >/dev/null; then
             usermod -a -G unbound "$EG_USER" || true
         fi
+        # freeradius: edgeguard muss die gerenderten clients.conf/authorize
+        # ins freeradius-lesbare Verzeichnis schreiben (setgid-Dir unten).
+        if getent group freeradius >/dev/null; then
+            usermod -a -G freeradius "$EG_USER" || true
+        fi
         # systemd-journal + adm: damit edgeguard-api `journalctl -u …`
         # ohne sudo lesen kann — wird für /api/v1/logs gebraucht
         # (zentrale Log-Übersicht über alle Services).
@@ -128,6 +133,15 @@ edgeguard ALL=(root) NOPASSWD: /usr/bin/systemctl enable kea-dhcp4-server.servic
 edgeguard ALL=(root) NOPASSWD: /bin/systemctl enable kea-dhcp4-server.service
 edgeguard ALL=(root) NOPASSWD: /usr/bin/systemctl disable kea-dhcp4-server.service
 edgeguard ALL=(root) NOPASSWD: /bin/systemctl disable kea-dhcp4-server.service
+# RADIUS (FreeRADIUS): Service-Lifecycle an radius_settings.enabled gekoppelt.
+edgeguard ALL=(root) NOPASSWD: /usr/bin/systemctl restart freeradius.service
+edgeguard ALL=(root) NOPASSWD: /bin/systemctl restart freeradius.service
+edgeguard ALL=(root) NOPASSWD: /usr/bin/systemctl stop freeradius.service
+edgeguard ALL=(root) NOPASSWD: /bin/systemctl stop freeradius.service
+edgeguard ALL=(root) NOPASSWD: /usr/bin/systemctl enable freeradius.service
+edgeguard ALL=(root) NOPASSWD: /bin/systemctl enable freeradius.service
+edgeguard ALL=(root) NOPASSWD: /usr/bin/systemctl disable freeradius.service
+edgeguard ALL=(root) NOPASSWD: /bin/systemctl disable freeradius.service
 edgeguard ALL=(root) NOPASSWD: /usr/bin/apt-get update -qq
 edgeguard ALL=(root) NOPASSWD: /usr/bin/apt-get update
 # Auto-Update-Toggle (Settings → Automatische Updates) schreibt/entfernt
@@ -251,6 +265,28 @@ SUDOERS
         ln -sfn /etc/edgeguard/kea/kea-dhcp4.conf /etc/kea/kea-dhcp4.conf
         systemctl disable --now kea-dhcp4-server.service 2>/dev/null || true
 
+        # FreeRADIUS: managed clients.conf + authorize unter /etc/edgeguard/
+        # freeradius (setgid → Dateien erben Gruppe freeradius, 0640 → der
+        # freeradius-Dienst kann lesen). Symlinks von den Distro-Pfaden.
+        # Dienst default AUS (kein RADIUS bis Operator aktiviert).
+        if getent group freeradius >/dev/null; then
+            install -d -m 2750 -o "$EG_USER" -g freeradius /etc/edgeguard/freeradius
+        else
+            install -d -m 0750 -o "$EG_USER" -g "$EG_USER" /etc/edgeguard/freeradius
+        fi
+        if [ -d /etc/freeradius/3.0 ]; then
+            if [ -e /etc/freeradius/3.0/clients.conf ] && [ ! -L /etc/freeradius/3.0/clients.conf ]; then
+                mv /etc/freeradius/3.0/clients.conf /etc/freeradius/3.0/clients.conf.distro-bak
+            fi
+            ln -sfn /etc/edgeguard/freeradius/clients.conf /etc/freeradius/3.0/clients.conf
+            if [ -e /etc/freeradius/3.0/mods-config/files/authorize ] && [ ! -L /etc/freeradius/3.0/mods-config/files/authorize ]; then
+                mv /etc/freeradius/3.0/mods-config/files/authorize /etc/freeradius/3.0/mods-config/files/authorize.distro-bak
+            fi
+            install -d /etc/freeradius/3.0/mods-config/files
+            ln -sfn /etc/edgeguard/freeradius/authorize /etc/freeradius/3.0/mods-config/files/authorize
+        fi
+        systemctl disable --now freeradius.service 2>/dev/null || true
+
         chmod 0440 /etc/sudoers.d/edgeguard
 
         # ── Sysctl-Profil für Edge-Gateway (NAT + HAProxy + Forwarding) ──