Distraction-Free Writing Mode

As a writer, I want a full-screen distraction-free writing mode that hides all navigation and UI chrome so I can focus entirely on writing without visual interruptions. Similar to iA Writer or Bear's focus mode — a clean canvas with just the text editor, a word count in the corner, and a minimal toolbar that fades out while typing. Could be toggled with a keyboard shortcut (e.g. Cmd+Shift+F) or a button in the editor toolbar.