Bridge legacy WebUI router imports

docs/COMPATIBILITY_INVENTORY.md

@@ -31,6 +31,7 @@ such as Redis degradation and language fallback are not compatibility paths.
 | Legacy tenant aliases in API response schemas | Preserves active-tenant response fields used by `0.1.x` clients. | Tagged `0.1.x` API window. | Remove at `0.2` with response-schema migration notes. |
 | Optional fields in Poll response references | Accepts providers built against the earlier Poll contract. | Tagged `0.1.x` runtime contract window. | Remove or require a new interface version at `0.2`. |
 | Legacy single-tenant summary providers | Allows modules without the batch provider introduced in `0.1.x`. | Tagged `0.1.x` module contract window. | Remove at `0.2` after manifests advertise the batch provider contract. |
+| WebUI `react-router-dom` build alias | Resolves tagged `0.1.x` module source imports to Core's single `react-router` runtime so one composition never loads two router contexts. | Tagged `0.1.x` WebUI source window. | Remove at `0.2` after every supported module tag imports `react-router` directly. |
 
 ## Removed Paths
 

webui/vite.config.ts

@@ -230,6 +230,9 @@ export default defineConfig({
       "read-excel-file"
     ],
     alias: [
+      // Tagged 0.1.x module sources used react-router-dom before the platform
+      // standardized on the package-neutral React Router 8 entry point.
+      { find: "react-router-dom", replacement: "react-router" },
       { find: "@govoplan/core-webui/app", replacement: fileURLToPath(new URL("./src/app.ts", import.meta.url)) },
       { find: "@govoplan/core-webui/definition-graph", replacement: fileURLToPath(new URL("./src/definitionGraph.ts", import.meta.url)) },
       { find: "@govoplan/core-webui/wysiwyg", replacement: fileURLToPath(new URL("./src/wysiwyg.ts", import.meta.url)) },