platform: modularize api/gui, add docs-tests-web foundation, and refresh root config

selective-vpn-api/app/transport_client_runtime_health.go

@@ -0,0 +1,85 @@
+package app
+
+import (
+	"strings"
+	"time"
+)
+
+func buildTransportHealthResponse(it TransportClient, now time.Time) TransportClientHealthResponse {
+	health := it.Health
+	if strings.TrimSpace(health.LastCheck) == "" {
+		if strings.TrimSpace(it.UpdatedAt) != "" {
+			health.LastCheck = it.UpdatedAt
+		} else {
+			health.LastCheck = now.Format(time.RFC3339)
+		}
+	}
+	if strings.TrimSpace(health.LastError) == "" {
+		health.LastError = strings.TrimSpace(it.Runtime.LastError.Message)
+	}
+	rt := transportRuntimeSnapshot(it, now)
+	code := ""
+	if it.Status == TransportClientDegraded || strings.TrimSpace(health.LastError) != "" {
+		code = "TRANSPORT_CLIENT_DEGRADED"
+	}
+	return TransportClientHealthResponse{
+		OK:       true,
+		Message:  "ok",
+		Code:     code,
+		ClientID: it.ID,
+		Kind:     it.Kind,
+		Status:   it.Status,
+		Latency:  health.LatencyMS,
+		LastErr:  health.LastError,
+		Health:   health,
+		Runtime:  rt,
+	}
+}
+
+func buildTransportMetricsResponse(it TransportClient, now time.Time) TransportClientMetricsResponse {
+	rt := transportRuntimeSnapshot(it, now)
+	return TransportClientMetricsResponse{
+		OK:       true,
+		Message:  "ok",
+		ClientID: it.ID,
+		Kind:     it.Kind,
+		Status:   it.Status,
+		Metrics:  rt.Metrics,
+		Runtime:  rt,
+	}
+}
+
+func applyTransportHealthProbeSnapshot(it TransportClient, backendID string, probe transportBackendHealthResult, now time.Time) TransportClient {
+	snapshot := it
+	ts := now.Format(time.RFC3339)
+	if strings.TrimSpace(backendID) != "" {
+		snapshot.Runtime.Backend = backendID
+	}
+	snapshot.Health.LastCheck = ts
+	if probe.LatencyMS > 0 {
+		snapshot.Health.LatencyMS = probe.LatencyMS
+	}
+	if probe.Status != "" {
+		snapshot.Status = normalizeTransportStatus(probe.Status)
+	}
+	if probe.OK {
+		if snapshot.Status != TransportClientDegraded {
+			snapshot.Health.LastError = ""
+		}
+		snapshot.Runtime.LastError = TransportClientError{}
+	} else {
+		msg := strings.TrimSpace(probe.Message)
+		if msg == "" {
+			msg = "transport health probe failed"
+		}
+		snapshot.Health.LastError = msg
+		snapshot.Runtime.LastError = TransportClientError{
+			Code:      strings.TrimSpace(probe.Code),
+			Message:   msg,
+			Retryable: probe.Retryable,
+			At:        ts,
+		}
+	}
+	snapshot.Runtime = transportRuntimeSnapshot(snapshot, now)
+	return snapshot
+}