refactor(edge): unify dynamic IP detection and prioritize IPv4 reporting

- Align agent, relay, and flared to dynamically resolve IP during heartbeat using the nodeip package (when not manually configured).
- Update GeoIP outbound IP strategy to prefer IPv4 HTTP client lookup using tcp4 dialer and fall back to dual-stack tcp.
- Optimize agent profile fingerprinting to exclude dynamic UptimeSeconds and ReportedAtUnix fields, preventing redundant updates.
- Refactor unit tests to prevent outbound network queries during tests.

internal/apps/agent/agent/runner_test.go

@@ -211,6 +211,7 @@ func TestRunnerKeepsHeartbeatWhenStartupSyncFails(t *testing.T) {
 			AccessToken:       "agent-token",
 			NodeName:          "edge-01",
 			NodeIP:            "10.0.0.8",
+			NodeIPConfigured:  true,
 			Version:           config.Version,
 			ExtVersion:        "1.27.1.2",
 			HeartbeatInterval: config.MillisecondDuration(10 * time.Millisecond),
@@ -264,6 +265,7 @@ func TestRunnerDoesNotExitOnHeartbeatOrSyncError(t *testing.T) {
 			AccessToken:       "agent-token",
 			NodeName:          "edge-01",
 			NodeIP:            "10.0.0.8",
+			NodeIPConfigured:  true,
 			Version:           config.Version,
 			ExtVersion:        "1.27.1.2",
 			HeartbeatInterval: config.MillisecondDuration(10 * time.Millisecond),
@@ -322,6 +324,7 @@ func TestRunnerReportsOpenrestyHealthAndExecutesRestart(t *testing.T) {
 			AccessToken:       "agent-token",
 			NodeName:          "edge-01",
 			NodeIP:            "10.0.0.8",
+			NodeIPConfigured:  true,
 			Version:           config.Version,
 			ExtVersion:        "1.27.1.2",
 			HeartbeatInterval: config.MillisecondDuration(10 * time.Millisecond),
@@ -375,6 +378,7 @@ func TestRunnerHeartbeatPayloadIncludesObservabilityExtensions(t *testing.T) {
 		Config: &config.Config{
 			NodeName:          "edge-observe-1",
 			NodeIP:            "10.0.0.51",
+			NodeIPConfigured:  true,
 			Version:           config.Version,
 			ExtVersion:        "1.27.1.2",
 			DataDir:           tempDir,
@@ -458,6 +462,7 @@ func TestRunnerReplaysBufferedObservabilityAfterHeartbeatRecovery(t *testing.T)
 			AccessToken:                "agent-token",
 			NodeName:                   "edge-buffer-01",
 			NodeIP:                     "10.0.0.52",
+			NodeIPConfigured:           true,
 			Version:                    config.Version,
 			ExtVersion:                 "1.27.1.2",
 			DataDir:                    tempDir,
@@ -537,6 +542,7 @@ func TestRunnerDiscoveryRegisterUpdatesTokenAndNodeID(t *testing.T) {
 			DiscoveryToken:    cfg.DiscoveryToken,
 			NodeName:          cfg.NodeName,
 			NodeIP:            cfg.NodeIP,
+			NodeIPConfigured:  cfg.NodeIPConfigured,
 			Version:           config.Version,
 			ExtVersion:        "1.27.1.2",
 			HeartbeatInterval: config.MillisecondDuration(10 * time.Millisecond),

internal/apps/agent/config/config.go

@@ -67,6 +67,7 @@ type Config struct {
 	HeartbeatInterval          MillisecondDuration `json:"heartbeat_interval"`
 	RequestTimeout             MillisecondDuration `json:"request_timeout"`
 	configPath                 string              `json:"-"`
+	NodeIPConfigured           bool                `json:"-"`
 }
 
 type configFile struct {
@@ -129,6 +130,7 @@ func Load(path string) (*Config, error) {
 	}
 	cfg.configPath = path
 	applyEnvOverrides(cfg)
+	cfg.NodeIPConfigured = cfg.NodeIP != ""
 	applyDefaults(cfg, filepath.Dir(path))
 	if err = validate(cfg); err != nil {
 		return nil, err

internal/apps/agent/heartbeat/cycle.go

@@ -14,6 +14,7 @@ import (
 	"github.com/Rain-kl/Wavelet/internal/apps/agent/state"
 	"github.com/Rain-kl/Wavelet/internal/apps/agent/updater"
 	edgeheartbeat "github.com/Rain-kl/Wavelet/internal/apps/edge/heartbeat"
+	"github.com/Rain-kl/Wavelet/internal/apps/edge/nodeip"
 )
 
 // SyncService is the interface used by Cycle to sync active configuration and WAF IP groups.
@@ -97,10 +98,16 @@ func (c *Cycle) NodePayload(ctx context.Context, nodeID string) protocol.NodePay
 	metricSnapshot := observability.BuildSnapshot(c.Config, c.StateStore)
 	openrestyObservation := observability.BuildOpenrestyObservation(managedOpenRestyMetrics)
 	healthEvents := observability.BuildHealthEvents(snapshot)
+
+	ip := c.Config.NodeIP
+	if !c.Config.NodeIPConfigured {
+		ip = nodeip.DetectWithContext(ctx)
+	}
+
 	payload := protocol.NodePayload{
 		NodeID:               nodeID,
 		Name:                 c.Config.NodeName,
-		IP:                   c.Config.NodeIP,
+		IP:                   ip,
 		Version:              c.Config.Version,
 		ExtVersion:           c.Config.ExtVersion,
 		CurrentVersion:       snapshot.CurrentVersion,

internal/apps/agent/observability/collector.go

@@ -148,7 +148,10 @@ func collectProfile(cfg *config.Config) *protocol.NodeSystemProfile {
 }
 
 func fingerprintProfile(profile *protocol.NodeSystemProfile) string {
-	raw, err := json.Marshal(profile)
+	cloned := *profile
+	cloned.UptimeSeconds = 0
+	cloned.ReportedAtUnix = 0
+	raw, err := json.Marshal(&cloned)
 	if err != nil {
 		return ""
 	}