Bookends v4.0.4

• New tokens %j (current chapter number) and %J (total chapters).
• New setting in Bookends settings: "Include current page in pages-left tokens". Toggles %L and %l between "n−1 → 0" and "n → 1".
• Fix: deleting a preset while previewing it could leak the preview's content into the active preset's file. Now re-applies the active preset before clearing the preview flag.