The editor's delete-translation button used `__('messages.documents.delete_translation') ?? __('messages.documents.delete')`, but `__()` returns the key string (not null) on miss so the `??` fallback never fires — the button rendered the literal key. Adds the missing key to all 16 locales (en+ja human-translated, others mirror en) and simplifies the blade to a single `__()` call.
Plan doc also reflects the SQLite dropIndex requirement found during Task 2.
Yutaka Kurosaki
1ce1fa23a4