fix: stabilize native road Cesium preview

scripts/lib/native-road.js

@@ -503,6 +503,7 @@ function compileJunctionSurfaces(model, junctionPlans, connectors, movements, di
       continue;
     }
     result.push({ type: "Feature", properties: { native_id: `junction:node/${nodeId}`, osm_node_id: nodeId, kind: segmentIds.size === 3 ? "t" : "cross", source_road_ids: approaches.flatMap((approach) => approach.roadIds).join(","), cutback_m: cutbackMeters, movement_count: junctionMovements.length, connector_count: junctionConnectors.length, boundary_mode: boundaryMode, rule: "junction-shared-cutback/v4-shared-node-split" }, geometry: { type: "Polygon", coordinates: [ring] } });
+    if (boundaryMode === "connector-convex-fallback") diagnostics.push(diagnostic("warning", `junction:node/${nodeId}`, [nodeId], "junction-connector-envelope-fallback", "路口面需要按转向路径的凸包兜底生成；请检查外缘和路缘与步行带是否符合实际。", node));
     diagnostics.push(diagnostic("info", `junction:node/${nodeId}`, [nodeId], "ordinary-junction-surface", "已按道路截面与转向路径生成普通路口面。", node));
   }
   return result;