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

selective-vpn-api/app/transport_singbox_profiles_card_get.go

@@ -0,0 +1,26 @@
+package app
+
+import "net/http"
+
+func handleTransportSingBoxProfileCardGet(w http.ResponseWriter, _ *http.Request, id string) {
+	singBoxProfilesMu.Lock()
+	st := loadSingBoxProfilesState()
+	singBoxProfilesMu.Unlock()
+
+	idx := findSingBoxProfileIndex(st.Items, id)
+	if idx < 0 {
+		writeJSON(w, http.StatusNotFound, SingBoxProfilesResponse{
+			OK:      false,
+			Code:    singBoxProfileCodeNotFound,
+			Message: "not found",
+		})
+		return
+	}
+	item := st.Items[idx]
+	writeJSON(w, http.StatusOK, SingBoxProfilesResponse{
+		OK:              true,
+		Message:         "ok",
+		ActiveProfileID: st.ActiveProfileID,
+		Item:            &item,
+	})
+}