fix(vscode): guard tag auto-close against replaced selections and stale round-trips

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

editors/vscode/src/extension.js

@@ -37,17 +37,31 @@ function registerAutoCloseTags(context, client) {
 
     const change = event.contentChanges[0];
     if (!change || (change.text !== ">" && change.text !== "/")) return;
+    // A replaced selection (overtype/select-and-type) makes `range.start + text.length`
+    // an incorrect offset for both the query and the insertion; decline rather than guess.
+    if (change.rangeLength !== 0) return;
 
     const editor = vscode.window.activeTextEditor;
     if (!editor || editor.document !== event.document) return;
 
+    const documentVersion = event.document.version;
     const position = change.range.start.translate(0, change.text.length);
+    if (!editor.selection.isEmpty || !editor.selection.active.isEqual(position)) return;
+
     const snippet = await client.sendRequest("wrn/tagComplete", {
       textDocument: { uri: event.document.uri.toString() },
       position: { line: position.line, character: position.character },
     });
     if (typeof snippet !== "string" || !snippet) return;
 
+    // The user may have kept typing during the round-trip; re-validate everything the
+    // insertion depends on before touching the document, since a stale offset would
+    // silently corrupt it.
+    if (vscode.window.activeTextEditor !== editor) return;
+    if (editor.document !== event.document) return;
+    if (editor.document.version !== documentVersion) return;
+    if (!editor.selection.isEmpty || !editor.selection.active.isEqual(position)) return;
+
     await editor.insertSnippet(new vscode.SnippetString(snippet), position);
   });