[management, client, proxy] add expose NetBird-only services over tunnel peers (#6226)

Adds a new "private" service mode for the reverse proxy: services reachable exclusively over the embedded WireGuard tunnel, gated by per-peer group membership instead of operator auth schemes.

Wire contract
- ProxyMapping.private (field 13): the proxy MUST call ValidateTunnelPeer and fail closed; operator schemes are bypassed.
- ProxyCapabilities.private (4) + supports_private_service (5): capability gate. Management never streams private mappings to proxies that don't claim the capability; the broadcast path applies the same filter via filterMappingsForProxy.
- ValidateTunnelPeer RPC: resolves an inbound tunnel IP to a peer, checks the peer's groups against service.AccessGroups, and mints a session JWT on success. checkPeerGroupAccess fails closed when a private service has empty AccessGroups.
- ValidateSession/ValidateTunnelPeer responses now carry peer_group_ids + peer_group_names so the proxy can authorise policy-aware middlewares without an extra management round-trip.
- ProxyInboundListener + SendStatusUpdate.inbound_listener: per-account inbound listener state surfaced to dashboards.
- PathTargetOptions.direct_upstream (11): bypass the embedded NetBird client and dial the target via the proxy host's network stack for upstreams reachable without WireGuard.

Data model
- Service.Private (bool) + Service.AccessGroups ([]string, JSON- serialised). Validate() rejects bearer auth on private services. Copy() deep-copies AccessGroups. pgx getServices loads the columns.
- DomainConfig.Private threaded into the proxy auth middleware. Request handler routes private services through forwardWithTunnelPeer and returns 403 on validation failure.
- Account-level SynthesizePrivateServiceZones (synthetic DNS) and injectPrivateServicePolicies (synthetic ACL) gate on len(svc.AccessGroups) > 0.

Proxy
- /netbird proxy --private (embedded mode) flag; Config.Private in proxy/lifecycle.go.
- Per-account inbound listener (proxy/inbound.go) binding HTTP/HTTPS on the embedded NetBird client's WireGuard tunnel netstack.
- proxy/internal/auth/tunnel_cache: ValidateTunnelPeer response cache with single-flight de-duplication and per-account eviction.
- Local peerstore short-circuit: when the inbound IP isn't in the account roster, deny fast without an RPC.
- proxy/server.go reports SupportsPrivateService=true and redacts the full ProxyMapping JSON from info logs (auth_token + header-auth hashed values now only at debug level).

Identity forwarding
- ValidateSessionJWT returns user_id, email, method, groups, group_names. sessionkey.Claims carries Email + Groups + GroupNames so the proxy can stamp identity onto upstream requests without an extra management round-trip on every cookie-bearing request.
- CapturedData carries userEmail / userGroups / userGroupNames; the proxy stamps X-NetBird-User and X-NetBird-Groups on r.Out from the authenticated identity (strips client-supplied values first to prevent spoofing).
- AccessLog.UserGroups: access-log enrichment captures the user's group memberships at write time so the dashboard can render group context without reverse-resolving stale memberships.

OpenAPI/dashboard surface
- ReverseProxyService gains private + access_groups; ReverseProxyCluster gains private + supports_private. ReverseProxyTarget target_type enum gains "cluster". ServiceTargetOptions gains direct_upstream. ProxyAccessLog gains user_groups.

client/internal/peer/status.go

@@ -185,9 +185,12 @@ func (s *StatusChangeSubscription) Events() chan map[string]RouterState {
 	return s.eventsChan
 }
 
-// Status holds a state of peers, signal, management connections and relays
+// Status holds a state of peers, signal, management connections and relays.
+// mux is an RWMutex so hot read paths (notably PeerStateByIP, called for
+// every private-service request) don't contend against each other.
+// Pure read methods take RLock; anything that mutates state takes Lock.
 type Status struct {
-	mux                   sync.Mutex
+	mux                   sync.RWMutex
 	peers                 map[string]State
 	changeNotify          map[string]map[string]*StatusChangeSubscription // map[peerID]map[subscriptionID]*StatusChangeSubscription
 	signalState           bool
@@ -283,8 +286,8 @@ func (d *Status) AddPeer(peerPubKey string, fqdn string, ip string, ipv6 string)
 
 // GetPeer adds peer to Daemon status map
 func (d *Status) GetPeer(peerPubKey string) (State, error) {
-	d.mux.Lock()
-	defer d.mux.Unlock()
+	d.mux.RLock()
+	defer d.mux.RUnlock()
 
 	state, ok := d.peers[peerPubKey]
 	if !ok {
@@ -294,8 +297,8 @@ func (d *Status) GetPeer(peerPubKey string) (State, error) {
 }
 
 func (d *Status) PeerByIP(ip string) (string, bool) {
-	d.mux.Lock()
-	defer d.mux.Unlock()
+	d.mux.RLock()
+	defer d.mux.RUnlock()
 
 	for _, state := range d.peers {
 		if state.IP == ip {
@@ -305,6 +308,25 @@ func (d *Status) PeerByIP(ip string) (string, bool) {
 	return "", false
 }
 
+// PeerStateByIP returns the full peer State for the given tunnel IP.
+// Matches against either the IPv4 (State.IP) or IPv6 (State.IPv6) tunnel
+// address so dual-stack peers are reachable on either family. Returns the
+// zero State and false when no peer matches or the input is empty.
+func (d *Status) PeerStateByIP(ip string) (State, bool) {
+	if ip == "" {
+		return State{}, false
+	}
+	d.mux.RLock()
+	defer d.mux.RUnlock()
+
+	for _, state := range d.peers {
+		if (state.IP != "" && state.IP == ip) || (state.IPv6 != "" && state.IPv6 == ip) {
+			return state, true
+		}
+	}
+	return State{}, false
+}
+
 // RemovePeer removes peer from Daemon status map
 func (d *Status) RemovePeer(peerPubKey string) error {
 	d.mux.Lock()
@@ -702,8 +724,8 @@ func (d *Status) UnsubscribePeerStateChanges(subscription *StatusChangeSubscript
 
 // GetLocalPeerState returns the local peer state
 func (d *Status) GetLocalPeerState() LocalPeerState {
-	d.mux.Lock()
-	defer d.mux.Unlock()
+	d.mux.RLock()
+	defer d.mux.RUnlock()
 	return d.localPeer.Clone()
 }
 
@@ -909,8 +931,8 @@ func (d *Status) DeleteResolvedDomainsStates(domain domain.Domain) {
 }
 
 func (d *Status) GetRosenpassState() RosenpassState {
-	d.mux.Lock()
-	defer d.mux.Unlock()
+	d.mux.RLock()
+	defer d.mux.RUnlock()
 	return RosenpassState{
 		d.rosenpassEnabled,
 		d.rosenpassPermissive,
@@ -918,14 +940,14 @@ func (d *Status) GetRosenpassState() RosenpassState {
 }
 
 func (d *Status) GetLazyConnection() bool {
-	d.mux.Lock()
-	defer d.mux.Unlock()
+	d.mux.RLock()
+	defer d.mux.RUnlock()
 	return d.lazyConnectionEnabled
 }
 
 func (d *Status) GetManagementState() ManagementState {
-	d.mux.Lock()
-	defer d.mux.Unlock()
+	d.mux.RLock()
+	defer d.mux.RUnlock()
 	return ManagementState{
 		d.mgmAddress,
 		d.managementState,
@@ -951,8 +973,8 @@ func (d *Status) UpdateLatency(pubKey string, latency time.Duration) error {
 
 // IsLoginRequired determines if a peer's login has expired.
 func (d *Status) IsLoginRequired() bool {
-	d.mux.Lock()
-	defer d.mux.Unlock()
+	d.mux.RLock()
+	defer d.mux.RUnlock()
 
 	// if peer is connected to the management then login is not expired
 	if d.managementState {
@@ -967,8 +989,8 @@ func (d *Status) IsLoginRequired() bool {
 }
 
 func (d *Status) GetSignalState() SignalState {
-	d.mux.Lock()
-	defer d.mux.Unlock()
+	d.mux.RLock()
+	defer d.mux.RUnlock()
 	return SignalState{
 		d.signalAddress,
 		d.signalState,
@@ -978,8 +1000,8 @@ func (d *Status) GetSignalState() SignalState {
 
 // GetRelayStates returns the stun/turn/permanent relay states
 func (d *Status) GetRelayStates() []relay.ProbeResult {
-	d.mux.Lock()
-	defer d.mux.Unlock()
+	d.mux.RLock()
+	defer d.mux.RUnlock()
 	if d.relayMgr == nil {
 		return d.relayStates
 	}
@@ -1008,8 +1030,8 @@ func (d *Status) GetRelayStates() []relay.ProbeResult {
 }
 
 func (d *Status) ForwardingRules() []firewall.ForwardRule {
-	d.mux.Lock()
-	defer d.mux.Unlock()
+	d.mux.RLock()
+	defer d.mux.RUnlock()
 	if d.ingressGwMgr == nil {
 		return nil
 	}
@@ -1018,16 +1040,16 @@ func (d *Status) ForwardingRules() []firewall.ForwardRule {
 }
 
 func (d *Status) GetDNSStates() []NSGroupState {
-	d.mux.Lock()
-	defer d.mux.Unlock()
+	d.mux.RLock()
+	defer d.mux.RUnlock()
 
 	// shallow copy is good enough, as slices fields are currently not updated
 	return slices.Clone(d.nsGroupStates)
 }
 
 func (d *Status) GetResolvedDomainsStates() map[domain.Domain]ResolvedDomainInfo {
-	d.mux.Lock()
-	defer d.mux.Unlock()
+	d.mux.RLock()
+	defer d.mux.RUnlock()
 	return maps.Clone(d.resolvedDomainsStates)
 }
 
@@ -1043,8 +1065,8 @@ func (d *Status) GetFullStatus() FullStatus {
 		LazyConnectionEnabled: d.GetLazyConnection(),
 	}
 
-	d.mux.Lock()
-	defer d.mux.Unlock()
+	d.mux.RLock()
+	defer d.mux.RUnlock()
 
 	fullStatus.LocalPeerState = d.localPeer
 
@@ -1219,8 +1241,8 @@ func (d *Status) SetWgIface(wgInterface WGIfaceStatus) {
 }
 
 func (d *Status) PeersStatus() (*configurer.Stats, error) {
-	d.mux.Lock()
-	defer d.mux.Unlock()
+	d.mux.RLock()
+	defer d.mux.RUnlock()
 	if d.wgIface == nil {
 		return nil, fmt.Errorf("wgInterface is nil, cannot retrieve peers status")
 	}

client/internal/peer/status_test.go

@@ -63,6 +63,33 @@ func TestUpdatePeerState(t *testing.T) {
 	assert.Equal(t, ip, state.IP, "ip should be equal")
 }
 
+func TestStatus_PeerStateByIP(t *testing.T) {
+	status := NewRecorder("https://mgm")
+	req := require.New(t)
+
+	req.NoError(status.AddPeer("pk-1", "peer-1.netbird", "100.64.0.10", ""))
+	req.NoError(status.AddPeer("pk-2", "peer-2.netbird", "100.64.0.11", ""))
+
+	state, ok := status.PeerStateByIP("100.64.0.10")
+	req.True(ok, "known tunnel IP should resolve to a peer state")
+	req.Equal("pk-1", state.PubKey, "matching state must carry the right pub key")
+	req.Equal("peer-1.netbird", state.FQDN, "matching state must carry the right FQDN")
+
+	_, ok = status.PeerStateByIP("100.64.0.99")
+	req.False(ok, "unknown IP must report ok=false")
+}
+
+func TestStatus_PeerStateByIP_MatchesIPv6(t *testing.T) {
+	status := NewRecorder("https://mgm")
+	req := require.New(t)
+
+	req.NoError(status.AddPeer("pk-1", "peer-1.netbird", "100.64.0.10", "fd00::1"))
+
+	state, ok := status.PeerStateByIP("fd00::1")
+	req.True(ok, "IPv6-only match must resolve to the peer state")
+	req.Equal("pk-1", state.PubKey, "matching state must carry the right pub key")
+}
+
 func TestStatus_UpdatePeerFQDN(t *testing.T) {
 	key := "abc"
 	fqdn := "peer-a.netbird.local"