Format panels now show what they are

Every format panel now shows a short description and relevant links right where you're browsing — not just on the main Formats page. Before, only the official Magic formats (Standard, Modern, Commander, etc.) got that treatment, and only on the main Formats overview. Now every panel, including a playgroup's own "Linked formats" list, shows a quick blurb about the format and links to rules, metagame info, card pool searches, or draft resources. Also fixed: opening a format from inside a playgroup and clicking "back" now takes you back to that playgroup's formats list, instead of dropping you on the general format overview.