[Routine - VT] fix(provider): flush pending debounced save on deactivation

src/extension.ts

@@ -117,6 +117,10 @@ export async function activate(context: vscode.ExtensionContext) {
     context.subscriptions.push(treeView);
     treeView.description = provider.computeScopeDescription();
 
+    // Flush any pending debounced save on deactivation so a change made
+    // just before VS Code closes isn't lost.
+    context.subscriptions.push({ dispose: () => provider.flushPendingSave() });
+
     // Pass the tree view to the provider for selection management
     provider.setTreeView(treeView);
 

src/provider.ts

@@ -331,6 +331,20 @@ export class TempFoldersProvider implements vscode.TreeDataProvider<vscode.TreeI
         }, 500);
     }
 
+    /**
+     * Synchronously flush a pending debounced save, if any.
+     * Call this on extension deactivation — otherwise an edit made just
+     * before VS Code closes can be lost, since the 500ms debounce timer
+     * never gets a chance to fire.
+     */
+    flushPendingSave(): void {
+        if (this.saveDebounceTimer) {
+            clearTimeout(this.saveDebounceTimer);
+            this.saveDebounceTimer = undefined;
+            this.saveGroupsImmediate();
+        }
+    }
+
     private saveGroupsImmediate() {
         if (this.groupManagers.size === 0) {
             console.warn('Cannot save VirtualTabs data: no GroupManagers available');