docs: add VS Code issue references for textDocuments lazy loading

Document why we use openTextDocument() instead of textDocuments.find()
in batch save operations. The textDocuments array has lazy loading
behavior and may not contain programmatically opened documents.

References:
- microsoft/vscode#33546
- microsoft/vscode#38665

Author: JohannesHoppe

src/commands/batch-organizer.ts

@@ -348,8 +348,11 @@ export class BatchOrganizer {
 
         // CRITICAL: Save all modified documents to disk!
         // workspace.applyEdit() only modifies in-memory documents, doesn't save!
-        // NOTE: We must explicitly open each document because files that weren't already
-        // open may not appear in workspace.textDocuments (race condition fix).
+        //
+        // NOTE: We must explicitly open each document because workspace.textDocuments
+        // has lazy loading behavior - it only contains documents that have been "activated".
+        // See: https://github.com/microsoft/vscode/issues/33546
+        // See: https://github.com/microsoft/vscode/issues/38665
         const saveFailed: string[] = [];
         let savedCount = 0;
         for (const [fileUri] of workspaceEdit.entries()) {