feat(todo): edit the file right in the TODO preview (#1129)

The TODO preview is an editor on the file, as in IntelliJ: a CodeMirror view attached to the real document, so edits share the buffer with editor tabs and Save All saves them; no editing switch. The caret lands on the selected item, also when another item of the same file is selected. Read-only files fall back to the read-only preview. Dirty buffers are held rather than released (releasing would auto-save or drop the edits), and previewText reads the held text.

Co-authored-by: qtvbwfn <[email protected]>

src/editor/core/model/attachment.ts

@@ -85,6 +85,7 @@ export async function attachDocument(manager: DocumentManager, path: string): Pr
     path,
     doc: model.doc,
     text: () => model.sync.localText.toString(),
+    uiMode: () => model.getMeta().uiMode,
     readOnly: model.getMeta().readOnly || model.virtual,
     extension: [
       model.manager.workspaceHistory.extension(historyTarget),