fix(reimport): retain intersection IDs for cruise routes

scripts/reimport-gpkg.js

@@ -78,6 +78,10 @@ try {
     const stagedPath = path.join(stagingDir, layerFile(layer));
     exportLayer(layer.id, stagedPath);
     const collection = readCollection(stagedPath, layer.id);
+    if (layer.id === "intersection_surface") {
+      restoreIntersectionSurfaceIds(collection);
+      fs.writeFileSync(stagedPath, JSON.stringify(collection));
+    }
     console.log(`${layer.id}\tfeatures=${collection.features.length}`);
     return { layer, stagedPath, collection };
   });
@@ -180,6 +184,9 @@ function exportLayer(layerName, destination) {
   // precision-reduction pass, which drops vertices that collapse at the given
   // resolution (measured: 28 points lost across 7 lane-arrow polygons).
   execFileSync(ogr2ogr, [
+    // GeoPackage reserves "id" as its FID column. Preserve it so the
+    // intersection surface can retain its osm2streets internal ID on export.
+    "-preserve_fid",
     "-f", "GeoJSON",
     destination,
     gpkgPath,
@@ -190,6 +197,23 @@ function exportLayer(layerName, destination) {
   });
 }
 
+function restoreIntersectionSurfaceIds(collection) {
+  for (const [index, feature] of collection.features.entries()) {
+    if (!feature || typeof feature !== "object") {
+      throw new Error(`intersection_surface feature ${index + 1} is invalid`);
+    }
+    const existingId = Number(feature.properties?.id);
+    if (Number.isInteger(existingId)) continue;
+    const fid = Number(feature.id);
+    if (!Number.isInteger(fid)) {
+      throw new Error(
+        `intersection_surface feature ${index + 1} is missing its osm2streets internal ID`,
+      );
+    }
+    feature.properties = { ...(feature.properties || {}), id: fid };
+  }
+}
+
 function readCollection(file, layerName) {
   let parsed;
   try {