fix(vscode): repair WRN language diagnostics and activation

.vscode/settings.json

@@ -2,7 +2,7 @@
   // Treat .wrn files as the WrNexus language (redundant with the extension, but
   // makes highlighting work the moment the repo is opened).
   "files.associations": {
-    "*.wrn": "wire"
+    "*.wrn": "wrn"
   },
 
   // Distinct colors for WrNexus's own attributes, so they're easy to spot inside