The editor already reflects UI opens/active/selection into EditorRegistry via the editor.open / editor.activate / editor.set-content IPC flow, so T-220's acceptance already holds for code files. Closes it with that rationale and folds the only real remainder -- the read-only reader's viewed file -- into T-221's clide status scope (focused file = active editor buffer OR active reader doc). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>