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>

internal/database/migrations/0042_radius.sql

@@ -0,0 +1,51 @@
+-- +goose Up
+-- +goose StatementBegin
+
+-- RADIUS (FreeRADIUS) — node-lokale Singleton-Settings (ob DIESE Node
+-- RADIUS betreibt + Listen). Clients/Users sind geteilte Config (repliziert).
+CREATE TABLE IF NOT EXISTS radius_settings (
+    id               INTEGER     PRIMARY KEY DEFAULT 1,
+    enabled          BOOLEAN     NOT NULL DEFAULT false,
+    listen_addresses TEXT        NOT NULL DEFAULT '',
+    created_at       TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at       TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    CONSTRAINT radius_settings_singleton CHECK (id = 1)
+);
+INSERT INTO radius_settings (id) VALUES (1) ON CONFLICT DO NOTHING;
+
+-- NAS-Clients (Geräte, die RADIUS-Requests senden): IP/CIDR + Shared Secret
+-- (verschlüsselt via secrets.Box).
+CREATE TABLE IF NOT EXISTS radius_clients (
+    id          BIGSERIAL   PRIMARY KEY,
+    name        TEXT        NOT NULL,
+    ipaddr      TEXT        NOT NULL,
+    secret_enc  BYTEA,
+    active      BOOLEAN     NOT NULL DEFAULT true,
+    description TEXT        NOT NULL DEFAULT '',
+    created_at  TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at  TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    CONSTRAINT radius_clients_name_unique UNIQUE (name)
+);
+
+-- Benutzer (PAP/CHAP): Name + Passwort (verschlüsselt; Cleartext nur zur
+-- Render-Zeit in die freeradius-lesbare authorize-Datei).
+CREATE TABLE IF NOT EXISTS radius_users (
+    id           BIGSERIAL   PRIMARY KEY,
+    username     TEXT        NOT NULL,
+    password_enc BYTEA,
+    active       BOOLEAN     NOT NULL DEFAULT true,
+    created_at   TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at   TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    CONSTRAINT radius_users_username_unique UNIQUE (username)
+);
+
+-- +goose StatementEnd
+
+-- +goose Down
+-- +goose StatementBegin
+
+DROP TABLE IF EXISTS radius_users;
+DROP TABLE IF EXISTS radius_clients;
+DROP TABLE IF EXISTS radius_settings;
+
+-- +goose StatementEnd