feat(vscode): close HTML tags as they are typed in .wrn files

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

editors/vscode/src/extension.js

@@ -23,6 +23,37 @@ async function recoverWrnLanguage(document) {
   }
 }
 
+/**
+ * Auto-close tags as they are typed.
+ *
+ * LSP has no request for this, so the client watches document changes and asks
+ * the server whether the tag should close. The server owns the decision because
+ * void elements and already-closed tags must not be closed.
+ */
+function registerAutoCloseTags(context, client) {
+  const listener = vscode.workspace.onDidChangeTextDocument(async (event) => {
+    if (event.document.languageId !== "wrn") return;
+    if (!vscode.workspace.getConfiguration("wrnexus.html").get("autoClosingTags", true)) return;
+
+    const change = event.contentChanges[0];
+    if (!change || (change.text !== ">" && change.text !== "/")) return;
+
+    const editor = vscode.window.activeTextEditor;
+    if (!editor || editor.document !== event.document) return;
+
+    const position = change.range.start.translate(0, change.text.length);
+    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;
+
+    await editor.insertSnippet(new vscode.SnippetString(snippet), position);
+  });
+
+  context.subscriptions.push(listener);
+}
+
 /** @param {vscode.ExtensionContext} context */
 async function activate(context) {
   for (const document of vscode.workspace.textDocuments) void recoverWrnLanguage(document);
@@ -43,6 +74,7 @@ async function activate(context) {
     { documentSelector: [{ scheme: "file", language: WRN_LANGUAGE_ID }] },
   );
   await client.start();
+  registerAutoCloseTags(context, client);
 }
 
 async function deactivate() {
@@ -51,4 +83,4 @@ async function deactivate() {
   if (running) await running.stop();
 }
 
-module.exports = { activate, deactivate, recoverWrnLanguage };
+module.exports = { activate, deactivate, recoverWrnLanguage, registerAutoCloseTags };