MarkdownDocument: typed source reads after a pause off the main thread; texts past 2 MiB are never read

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/documents/document/edit.rs

@@ -36,7 +36,7 @@ impl MarkdownDocument {
         };
         let written = self.commit(cx);
         if written.is_some() {
-            self.reparse(cx);
+            self.reparse(true, cx);
         }
         if !self.read_now(cx) {
             return log::warn!("markdown document: pressed while the text is read again");