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

selective-vpn-api/app/transport_client_runtime_normalize_config.go

@@ -0,0 +1,19 @@
+package app
+
+const transportSingBoxUnitTemplate = "singbox@.service"
+
+func normalizeTransportClientConfig(kind TransportClientKind, cfg map[string]any) (map[string]any, bool) {
+	if kind != TransportClientSingBox {
+		return cfg, false
+	}
+	out := cloneMap(cfg)
+	if out == nil {
+		out = map[string]any{}
+	}
+	cur := transportConfigString(out, "unit")
+	if cur == transportSingBoxUnitTemplate {
+		return out, cfg == nil
+	}
+	out["unit"] = transportSingBoxUnitTemplate
+	return out, true
+}