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/services/users/users.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/jackc/pgx/v5"
 	"github.com/jackc/pgx/v5/pgxpool"
+	"github.com/pquerna/otp/totp"
 	"golang.org/x/crypto/bcrypt"
 )
 
@@ -27,22 +28,30 @@ type User struct {
 	Email       string     `json:"email"`
 	Role        string     `json:"role"`
 	Active      bool       `json:"active"`
+	TOTPEnabled bool       `json:"totp_enabled"`
 	LastLoginAt *time.Time `json:"last_login_at"`
 	CreatedAt   time.Time  `json:"created_at"`
 	UpdatedAt   time.Time  `json:"updated_at"`
 }
 
+// AuthInfo is returned by FindForAuth — contains credentials needed during login.
+type AuthInfo struct {
+	User
+	PasswordHash string
+	TOTPSecret   *string
+}
+
 type Repo struct {
 	pool *pgxpool.Pool
 }
 
 func New(pool *pgxpool.Pool) *Repo { return &Repo{pool: pool} }
 
-const selectCols = `id, email, role, active, last_login_at, created_at, updated_at`
+const selectCols = `id, email, role, active, totp_enabled, last_login_at, created_at, updated_at`
 
 func scan(row pgx.Row) (User, error) {
 	var u User
-	err := row.Scan(&u.ID, &u.Email, &u.Role, &u.Active,
+	err := row.Scan(&u.ID, &u.Email, &u.Role, &u.Active, &u.TOTPEnabled,
 		&u.LastLoginAt, &u.CreatedAt, &u.UpdatedAt)
 	return u, err
 }
@@ -71,7 +80,7 @@ func (r *Repo) FindByEmail(ctx context.Context, email string) (User, string, err
 	var hash string
 	err := r.pool.QueryRow(ctx,
 		`SELECT `+selectCols+`, password_hash FROM users WHERE lower(email)=lower($1)`,
-		email).Scan(&u.ID, &u.Email, &u.Role, &u.Active,
+		email).Scan(&u.ID, &u.Email, &u.Role, &u.Active, &u.TOTPEnabled,
 		&u.LastLoginAt, &u.CreatedAt, &u.UpdatedAt, &hash)
 	if errors.Is(err, pgx.ErrNoRows) {
 		return u, "", ErrNotFound
@@ -79,6 +88,70 @@ func (r *Repo) FindByEmail(ctx context.Context, email string) (User, string, err
 	return u, hash, err
 }
 
+// FindForAuth returns full auth credentials including TOTP secret. ErrNotFound if absent.
+func (r *Repo) FindForAuth(ctx context.Context, email string) (*AuthInfo, error) {
+	var a AuthInfo
+	err := r.pool.QueryRow(ctx,
+		`SELECT `+selectCols+`, password_hash, totp_secret FROM users WHERE lower(email)=lower($1)`,
+		email).Scan(&a.ID, &a.Email, &a.Role, &a.Active, &a.TOTPEnabled,
+		&a.LastLoginAt, &a.CreatedAt, &a.UpdatedAt, &a.PasswordHash, &a.TOTPSecret)
+	if errors.Is(err, pgx.ErrNoRows) {
+		return nil, ErrNotFound
+	}
+	return &a, err
+}
+
+// GenerateTOTPSecret creates a new TOTP secret for the given email and returns
+// the secret + the otpauth:// provisioning URI (for QR code rendering in the UI).
+// The secret is NOT saved yet — call ConfirmTOTP after the user verifies the code.
+func GenerateTOTPSecret(email string) (secret, uri string, err error) {
+	key, err := totp.Generate(totp.GenerateOpts{
+		Issuer:      "EdgeGuard",
+		AccountName: email,
+	})
+	if err != nil {
+		return "", "", err
+	}
+	return key.Secret(), key.URL(), nil
+}
+
+// ConfirmTOTP verifies the given TOTP code against the (not-yet-saved) secret
+// and, on success, persists it and enables TOTP for the user.
+func (r *Repo) ConfirmTOTP(ctx context.Context, userID int64, secret, code string) error {
+	if !totp.Validate(code, secret) {
+		return errors.New("invalid_totp_code")
+	}
+	tag, err := r.pool.Exec(ctx,
+		`UPDATE users SET totp_secret=$1, totp_enabled=true, updated_at=NOW() WHERE id=$2`,
+		secret, userID)
+	if err != nil {
+		return err
+	}
+	if tag.RowsAffected() == 0 {
+		return ErrNotFound
+	}
+	return nil
+}
+
+// DisableTOTP clears the TOTP secret and disables 2FA for the given user.
+func (r *Repo) DisableTOTP(ctx context.Context, userID int64) error {
+	tag, err := r.pool.Exec(ctx,
+		`UPDATE users SET totp_secret=NULL, totp_enabled=false, updated_at=NOW() WHERE id=$1`,
+		userID)
+	if err != nil {
+		return err
+	}
+	if tag.RowsAffected() == 0 {
+		return ErrNotFound
+	}
+	return nil
+}
+
+// VerifyTOTP checks a live TOTP code against the stored secret.
+func VerifyTOTP(secret, code string) bool {
+	return totp.Validate(code, secret)
+}
+
 func (r *Repo) Count(ctx context.Context) (int, error) {
 	var n int
 	err := r.pool.QueryRow(ctx, `SELECT COUNT(*) FROM users`).Scan(&n)