fix(vscode): repair WRN language diagnostics and activation

editors/vscode/README.md

@@ -735,6 +735,22 @@ Recommended VS Code configuration:
 }
 ```
 
+## Troubleshooting language detection
+
+Files ending in `.wrn` should show `WRNexus` in the VS Code status bar. If an
+older workspace setting maps `*.wrn` to the legacy `wire` language ID, replace
+it with:
+
+```json
+"files.associations": {
+  "*.wrn": "wrn"
+}
+```
+
+Then run **Developer: Reload Window**. The extension also repairs open `.wrn`
+documents that VS Code classified as Plain Text or as the legacy `wire`
+language.
+
 ## Privacy
 
 The extension does not collect telemetry.