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

selective-vpn-api/app/transport_health_refresh_probe.go

@@ -0,0 +1,81 @@
+package app
+
+import (
+	"strings"
+	"time"
+)
+
+func transportRunHealthProbe(clientID string) {
+	id := strings.TrimSpace(clientID)
+	if id == "" {
+		return
+	}
+	transportHealthSWR.acquire()
+	defer transportHealthSWR.release()
+
+	now := time.Now().UTC()
+
+	transportMu.Lock()
+	st := loadTransportClientsState()
+	idx := findTransportClientIndex(st.Items, id)
+	if idx < 0 {
+		transportMu.Unlock()
+		transportHealthSWR.finishError(id, "client not found", now)
+		return
+	}
+	prev := st.Items[idx]
+	transportMu.Unlock()
+
+	backend := selectTransportBackend(prev)
+	probe := backend.Health(prev)
+	backendID := backend.ID()
+
+	transportMu.Lock()
+	st = loadTransportClientsState()
+	idx = findTransportClientIndex(st.Items, id)
+	if idx < 0 {
+		transportMu.Unlock()
+		transportHealthSWR.finishError(id, "client not found", now)
+		return
+	}
+	prev = st.Items[idx]
+	next := applyTransportHealthProbeSnapshot(prev, backendID, probe, now)
+
+	healthChanged := transportHealthChanged(prev, next)
+	persist := transportShouldPersistHealthSnapshot(prev, next, now)
+
+	if persist {
+		st.Items[idx] = next
+		if err := saveTransportClientsState(st); err != nil {
+			transportMu.Unlock()
+			transportHealthSWR.finishError(id, "save failed: "+err.Error(), now)
+			return
+		}
+	}
+	transportMu.Unlock()
+
+	if healthChanged {
+		events.push("transport_client_health_changed", map[string]any{
+			"id":         id,
+			"status":     next.Status,
+			"latency_ms": next.Health.LatencyMS,
+			"last_error": strings.TrimSpace(next.Health.LastError),
+			"last_check": strings.TrimSpace(next.Health.LastCheck),
+		})
+		publishTransportRuntimeObservabilitySnapshotChanged(
+			"transport_client_health_changed",
+			[]string{id},
+			nil,
+		)
+	}
+
+	if probe.OK {
+		transportHealthSWR.finishSuccess(id, now)
+		return
+	}
+	msg := strings.TrimSpace(probe.Message)
+	if msg == "" {
+		msg = "transport health probe failed"
+	}
+	transportHealthSWR.finishError(id, msg, now)
+}