feat: add immutable road revision storage

workbench/server.js

@@ -9,6 +9,7 @@ const { generate, validateDocument, runtime } = require('../src/native-traffic-s
 const { convertGeoJson } = require('../src/reference/gaode');
 const { exportNativeRoadPackage } = require('../src/export/native-road-package');
 const { compileInput } = require('../src/compile/compiler');
+const { ensureRevisionStore } = require('../src/compile/road-revisions');
 
 function startWorkbench({
   area = null,
@@ -167,6 +168,9 @@ function handle(request, response, session) {
 }
 
 function state(area, junctionReference = null, debug = false) {
+  // This is the read entry point for both a fresh import and a reopened legacy
+  // workspace. Initialization only adds the v2 layout; it never rewrites v1 files.
+  ensureRevisionStore(path.dirname(area.input));
   const nativeDir = area.outputs.nativeRoadDir;
   const osm2streetsRoadSurface = area.outputs.geojsonDir
     ? path.join(area.outputs.geojsonDir, 'road_surface.geojson')
@@ -325,6 +329,7 @@ function readUpload(request, session) {
     );
     try {
       const compiled = compileInput(input);
+      ensureRevisionStore(root);
       session.area = compiled.area;
       return compiled;
     } catch (error) {